Light-emitting devices

Abstract

To provide a novel organometallic complex with excellent heat resistance. [Solution] An organometallic complex comprising iridium and a ligand, wherein the ligand has a pyrazine skeleton, iridium is bonded to the nitrogen at position 1 of the pyrazine skeleton, an aryl group having a cyano group as a substituent is bonded to position 5 of the pyrazine skeleton, and hydrogen, alkyl group, or alkoxy group is independently bonded to positions 3 and 6 of the pyrazine skeleton, comprising a structure represented by the following general formula (G1). JPEG2026108722000054.jpg45167

Description

[Technical Field]

[0001] One aspect of the present invention relates to organometallic complexes. In particular, it relates to organometallic complexes capable of converting energy in a triplet excited state into light emission. It also relates to light-emitting devices, light-emitting apparatuses, electronic devices, and lighting apparatuses using organometallic complexes. However, one aspect of the present invention is not limited to the above-mentioned technical fields. The technical fields of one aspect of the invention disclosed herein relate to products, methods, or manufacturing methods. Alternatively, one aspect of the present invention relates to processes, machines, manufacturers, or compositions of matter. Therefore, more specifically, examples of technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, liquid crystal display devices, energy storage devices, memory devices, methods for driving them, or methods for manufacturing them. [Background technology]

[0002] Light-emitting devices (also called organic EL elements), which have an organic compound that emits light between a pair of electrodes, are attracting attention as next-generation flat panel displays due to their characteristics such as being thin, lightweight, fast response, and low voltage drive. In these light-emitting devices, when a voltage is applied, electrons and holes injected from the electrodes recombine, causing the light-emitting material to enter an excited state, and light is emitted when this excited state returns to the ground state. The types of excited states include singlet excited states (S * ) and triplet excited state (T * ) and luminescence from the singlet excited state is called fluorescence, and luminescence from the triplet excited state is called phosphorescence. Furthermore, the statistical generation ratio of these in light-emitting devices is S * :T * It is believed that the ratio is 1:3.

[0003] Furthermore, among the above-mentioned light-emitting materials, compounds that can convert the energy in the singlet excited state into light emission are called fluorescent compounds (fluorescent materials), and compounds that can convert the energy in the triplet excited state into light emission are called phosphorescent compounds (phosphorescent materials).

[0004] Therefore, based on the above generation ratios, the theoretical limits of the internal quantum efficiency (the ratio of photons generated to injected carriers) in light-emitting devices using each of the above-mentioned light-emitting materials are 25% when using fluorescent materials and 100% when using phosphorescent materials.

[0005] In other words, light-emitting devices using phosphorescent materials can achieve higher efficiency compared to light-emitting devices using fluorescent materials. Therefore, in recent years, there has been a great deal of activity in developing various types of phosphorescent materials. In particular, organometallic complexes with iridium as the central metal have attracted attention due to their high phosphorescence quantum yield (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2009-23938 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As reported in Patent Document 1 mentioned above, progress is being made in developing phosphorescent materials that exhibit excellent properties, but there is a need for the development of new materials that exhibit even better properties.

[0008] Therefore, in one aspect of the present invention, a novel organometallic complex is provided. In another aspect of the present invention, a novel organometallic complex exhibiting good red emission is provided. In yet another aspect of the present invention, a novel organometallic complex having an emission spectrum with a narrow full width at half maximum is provided. In yet another aspect of the present invention, a novel light-emitting device with a good lifetime is provided. In yet another aspect of the present invention, a novel organometallic complex exhibiting red emission with high quantum efficiency is provided. In yet another aspect of the present invention, a novel organometallic complex that can be used in the EL layer of a light-emitting device is provided. In yet another aspect of the present invention, a novel organometallic complex that can provide a light-emitting device with high luminous efficiency is provided. In yet another aspect of the present invention, a novel organometallic complex that can provide a light-emitting device with high luminous efficiency is provided. In yet another aspect of the present invention, a novel light-emitting device is provided. In yet another aspect of the present invention, a novel light-emitting device, a novel electronic device, or a novel lighting device is provided. [Means for solving the problem]

[0009] One aspect of the present invention is an organometallic complex having a ligand containing a pyrazine skeleton, wherein iridium is bonded to the nitrogen at position 1 of the pyrazine skeleton, the 3rd and 6th positions of the pyrazine skeleton each independently contain one of hydrogen, an alkyl group, or an alkoxy group, the 5th position of the pyrazine skeleton is bonded to an aryl group having a cyano group as a substituent, the 2nd position of the pyrazine skeleton is bonded to an aromatic hydrocarbon group, and some of the carbon atoms of the aromatic hydrocarbon group are bonded to iridium, and the complex has a structure represented by the following general formula (G1).

[0010] [ka]

[0011] However, in the general formula (G1), A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. Also, A rrepresents an aryl group having 6 to 25 carbon atoms with at least one cyano group as a substituent. Also, R 1 and R 2 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

[0012] Another aspect of the present invention is an organometallic complex containing a structure represented by the following general formula (G2).

[0013]

Chemical formula

[0014] However, in the general formula (G2), A r represents an aryl group having 6 to 25 carbon atoms with at least one cyano group as a substituent. Also, R 1 and R 2 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 to R 6 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, a halogen group, or a trifluoromethyl group.

[0015] Another aspect of the present invention is an organometallic complex having a structure represented by the following general formula (G3).

[0016]

Chemical formula

[0017] However, in the general formula (G3), A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. Also, A r represents an aryl group having 6 to 25 carbon atoms with at least one cyano group as a substituent. Also, R 1 and R 2Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, or a C1-C6 alkoxy group. L represents a monoanionic ligand.

[0018] Another aspect of the present invention is an organometallic complex having a structure represented by the following general formula (G4).

[0019] [ka]

[0020] However, in the general formula (G4), A r This represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 ~R 6 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. L represents a monoanionic ligand.

[0021] In each of the above configurations, the monoanionic ligand is preferably an organometallic complex that is a monoanionic bidentate chelate ligand having a β-diketone structure, a monoanionic bidentate chelate ligand having a carboxyl group, a monoanionic bidentate chelate ligand having a phenolic hydroxyl group, a monoanionic bidentate chelate ligand in which both coordinating elements are nitrogen, or an aromatic heterocyclic bidentate ligand that forms a metal-carbon bond with iridium by cyclometalation.

[0022] Furthermore, in each of the above configurations, the monoanionic ligand is preferably one of the following general formulas (L1) to (L6).

[0023] [ka]

[0024] However, in the above general formulas (L1) to (L6), R 71 ~R 94 Each of these independently represents hydrogen, or one of the following: a substituted or unsubstituted C1-C10 alkyl group, a halogen group, a vinyl group, a substituted or unsubstituted C1-C10 haloalkyl group, a substituted or unsubstituted C1-C10 alkoxy group, or a substituted or unsubstituted C1-C10 alkylthio group. Also, A 1 ~A 3 Each of these independently bonds with either nitrogen or hydrogen. 2 hybridized carbon or substituent sp 2 It represents a hybrid carbon, and the substituent represents one of the following: an alkyl group having 1 to 10 carbon atoms, a halogen group, a haloalkyl group having 1 to 10 carbon atoms, or a phenyl group, B 1 ~B 8 Each of these atoms independently bonds with either nitrogen or hydrogen, forming sp² atoms. 2 hybridized carbon or substituent sp 2 It represents a hybrid carbon atom, and the substituent represents one of the following: an alkyl group having 1 to 10 carbon atoms, a halogen group, a haloalkyl group having 1 to 10 carbon atoms, or a phenyl group.

[0025] Another aspect of the present invention is an organometallic complex represented by the following general formula (G5).

[0026] [ka]

[0027] However, in the general formula (G5), R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 ~R 6 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group.7 ~R 11 Each of these independently represents one of the following: hydrogen, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, a substituted or unsubstituted C3-C12 heteroaryl group, or a cyano group, with at least one representing a cyano group. 71 ~R 73 Each of these independently represents hydrogen, or one of the following: a substituted or unsubstituted C1-C10 alkyl group, a halogen group, a vinyl group, a substituted or unsubstituted C1-C10 haloalkyl group, a substituted or unsubstituted C1-C10 alkoxy group, or a substituted or unsubstituted C1-C10 alkylthio group.

[0028] Another aspect of the present invention is an organometallic complex represented by the following general formula (G6).

[0029] [ka]

[0030] However, in the general formula (G6), R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 and R 5 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. 7 ~R 11 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, a substituted or unsubstituted C3-C12 heteroaryl group, or a cyano group, with at least one representing a cyano group. 71 ~R 73Each of these independently represents one of the following: hydrogen, a C1-C10 alkyl group, a halogen group, a vinyl group, a C1-C10 haloalkyl group, a C1-C10 alkoxy group, or a C1-C10 alkylthio group.

[0031] Another aspect of the present invention is an organometallic complex represented by the following general formula (G7).

[0032] [ka]

[0033] However, in the general formula (G7), R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 ~R 6 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. 7 ~R 11 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms, or a cyano group, with at least one representing a cyano group.

[0034] Another aspect of the present invention is an organometallic complex represented by the following general formula (G8).

[0035] [ka]

[0036] However, in the general formula (G8), R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 and R 5Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. 7 ~R 11 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms, or a cyano group, with at least one representing a cyano group.

[0037] Another aspect of the present invention is an organometallic complex represented by structural formula (100) or structural formula (101).

[0038] [ka]

[0039] Another aspect of the present invention is a light-emitting device using at least one of the organometallic complexes described above. For example, a light-emitting device according to one aspect of the present invention has an EL layer between a pair of electrodes, and the EL layer has at least one of the organometallic complexes described above. Alternatively, for example, the EL layer has a light-emitting layer, and the light-emitting layer has at least one of the organometallic complexes described above.

[0040] Another aspect of the present invention is a light-emitting device having the above-mentioned light-emitting device and a transistor or substrate.

[0041] Another aspect of the present invention is an electronic device having the above-mentioned light-emitting device and a microphone, a camera, an operating button, an external connection part, or a speaker.

[0042] Another aspect of the present invention is an electronic device having the above-mentioned light-emitting device and a housing or touch sensor function.

[0043] Another aspect of the present invention is a lighting device having the above-mentioned light-emitting device and a housing, cover, or support base. [Effects of the Invention]

[0044] In one aspect of the present invention, a novel organometallic complex can be provided. In another aspect of the present invention, a novel organometallic complex exhibiting good red emission can be provided. In yet another aspect of the present invention, a novel organometallic complex having an emission spectrum with a narrow half-width can be provided. In yet another aspect of the present invention, a novel light-emitting device with a good lifetime can be provided. In yet another aspect of the present invention, a novel organometallic complex exhibiting high quantum efficiency red emission can be provided. In yet another aspect of the present invention, a novel organometallic complex that can be used in the EL layer of a light-emitting device can be provided. In yet another aspect of the present invention, a novel organometallic complex that can provide a light-emitting device with high luminous efficiency can be provided. In yet another aspect of the present invention, a novel organometallic complex that can provide a light-emitting device with high luminous efficiency can be provided. In yet another aspect of the present invention, a novel light-emitting device can be provided. In yet another aspect of the present invention, a novel light-emitting device, a novel electronic device, or a novel lighting device can be provided.

[0045] Furthermore, the description of these effects does not preclude the existence of other effects. Also, one aspect of the present invention does not necessarily have to possess all of these effects. Moreover, other effects will naturally become clear from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc. [Brief explanation of the drawing]

[0046] [Figure 1] Figures 1A, 1B, and 1C are schematic diagrams of the light-emitting device. [Figure 2] Figures 2A and 2B are conceptual diagrams of an active matrix type light-emitting device. [Figure 3]Figures 3A and 3B are conceptual diagrams of an active matrix type light-emitting device. [Figure 4] Figure 4 is a conceptual diagram of an active matrix type light-emitting device. [Figure 5] Figures 5A and 5B are conceptual diagrams of a passive matrix type light-emitting device. [Figure 6] Figures 6A and 6B are diagrams representing lighting devices. [Figure 7] Figures 7A, 7B1, 7B2, and 7C are diagrams representing electronic devices. [Figure 8] Figures 8A, 8B, and 8C represent electronic devices. [Figure 9] Figure 9 is a diagram representing a lighting device. [Figure 10] Figure 10 is a diagram representing a lighting device. [Figure 11] Figure 11 is a diagram representing an in-vehicle display device and lighting system. [Figure 12] Figures 12A and 12B are diagrams representing electronic devices. [Figure 13] Figures 13A, 13B, and 13C are diagrams representing electronic devices. [Figure 14] Figure 14 is the 1H NMR chart of [Ir(dmmppr-mCP)2(debm)]. [Figure 15] Figure 15 shows the absorption and emission spectra of [Ir(dmmppr-mCP)2(debm)] in solution. [Figure 16] Figure 16 is the 1H NMR chart of [Ir(tBummppr-mCP)2(debm)]. [Figure 17] Figure 17 shows the absorption and emission spectra of [Ir(tBummppr-mCP)2(debm)] in solution. [Figure 18] Figure 18 is a diagram illustrating a light-emitting device. [Figure 19] Figure 19 shows the current density-luminance characteristics of light-emitting devices 1, 2, 3, and 4. [Figure 20]Figure 20 shows the voltage-luminance characteristics of light-emitting device 1, light-emitting device 2, light-emitting device 3, and light-emitting device 4. [Figure 21] Figure 21 shows the luminance-current efficiency characteristics of light-emitting device 1, light-emitting device 2, light-emitting device 3, and light-emitting device 4. [Figure 22] Figure 22 shows the voltage-current characteristics of light-emitting device 1, light-emitting device 2, light-emitting device 3, and light-emitting device 4. [Figure 23] Figure 23 shows the emission spectra of light-emitting device 1, light-emitting device 2, light-emitting device 3, and light-emitting device 4. [Figure 24] Figure 24 shows the reliability of light-emitting devices 1, 2, 3, and 4. [Figure 25] Figure 25 shows the current density-luminance characteristics of the light-emitting device 5. [Figure 26] Figure 26 shows the voltage-luminance characteristics of the light-emitting device 5. [Figure 27] Figure 27 shows the luminance-current efficiency characteristics of the light-emitting device 5. [Figure 28] Figure 28 shows the voltage-current characteristics of the light-emitting device 5. [Figure 29] Figure 29 shows the emission spectrum of the light-emitting device 5. [Figure 30] Figure 30 shows the reliability of the light-emitting device 5. [Modes for carrying out the invention]

[0047] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following description, and its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention shall not be interpreted as being limited to the contents of the embodiments shown below.

[0048] It should be noted that the terms "film" and "layer" can be interchanged depending on the context or situation. For example, the term "conductive layer" can sometimes be changed to "conductive film." Or, for example, the term "insulating film" can sometimes be changed to "insulating layer."

[0049] (Embodiment 1) This embodiment describes an organometallic complex, which is one aspect of the present invention.

[0050] The organometallic complex shown in this embodiment has iridium as the central metal and a ligand containing a pyrazine skeleton, with iridium bonded to the nitrogen at position 1 of the pyrazine skeleton, the 3rd and 6th positions of the pyrazine skeleton each independently having one of hydrogen, an alkyl group, or an alkoxy group, the 5th position of the pyrazine skeleton bonded to an aryl group having a cyano group as a substituent, the 2nd position of the pyrazine skeleton bonded to an aromatic hydrocarbon group, and some of the carbon atoms of the aromatic hydrocarbon group bonded to iridium.

[0051] Furthermore, the organometallic complex shown in this embodiment has a first ligand and a second ligand bonded to iridium, which is the central metal, the first ligand containing a pyrazine skeleton, with iridium bonded to the nitrogen at position 1 of the pyrazine skeleton, the third and sixth positions of the pyrazine skeleton each independently having one of hydrogen, an alkyl group, or an alkoxy group, the fifth position of the pyrazine skeleton bonded to an aryl group having a cyano group as a substituent, the second position of the pyrazine skeleton bonded to an aromatic hydrocarbon group, some of the carbon atoms of the aromatic hydrocarbon group bonded to iridium, and the second ligand is a monoanionic ligand organometallic complex.

[0052] In particular, the second ligand is an organometallic complex that is a monoanionic bidentate chelate ligand having a β-diketone structure, a monoanionic bidentate chelate ligand having a carboxyl group, a monoanionic bidentate chelate ligand having a phenolic hydroxyl group, a monoanionic bidentate chelate ligand in which both coordinating elements are nitrogen, or an aromatic heterocyclic bidentate ligand that can form a metal-carbon bond with iridium by cyclometalation.

[0053] In one embodiment of the present invention, an organometallic complex has a hydrogen atom, an alkyl group, or an alkoxy group independently bonded to the 3rd and 6th positions of the pyrazine skeleton, and an aryl group having a cyano group as a substituent bonded to the 5th position of the pyrazine skeleton.

[0054] Having a cyano group as a substituent on the aryl group bonded at position 5 of the pyrazine skeleton improves resistance to decomposition during sublimation. On the other hand, the presence of a cyano group tends to shift the emission wavelength to longer wavelengths, and especially when a pyrazine skeleton is present, the emission color tends to become a deep red. A deep red emission color tends to result in low current efficiency. Therefore, hydrogen, alkyl, or alkoxy groups are independently provided as substituents at positions 3 and 6 of the pyrazine skeleton.

[0055] By independently adding hydrogen, alkyl, or alkoxy groups as substituents at positions 3 and 6 of the pyrazine skeleton, the emission wavelength is shifted to shorter wavelengths compared to the case where an aryl group is present at at least one of positions 3 and 6 of the pyrazine skeleton. As a result, emission at longer wavelengths, which have poor luminescence, is reduced, and current efficiency can be improved. In addition, the sublimation temperature is lower than when an aryl group is present at at least one of positions 3 and 6 of the pyrazine skeleton.

[0056] Accordingly, one embodiment of the present invention is characterized in that a hydrogen atom, an alkyl group, or an alkoxy group is independently bonded to the 3rd and 6th positions of the pyrazine skeleton, and the aryl group bonded to the 5th position of the pyrazine skeleton has a cyano group as a substituent.

[0057] The organometallic complex shown in this embodiment is an organometallic complex containing a structure represented by the following general formula (G1).

[0058] [ka]

[0059] In general formula (G1), A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. r This represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

[0060] The organometallic complex shown in this embodiment is an organometallic complex containing a structure represented by the following general formula (G2).

[0061] [ka]

[0062] Note that in the general formula (G2), A r This represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 ~R 6 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group.

[0063] The organometallic complex shown in this embodiment is an organometallic complex having a structure represented by the following general formula (G3).

[0064] [ka]

[0065] In general formula (G3), A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. r This represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, or a C1-C6 alkoxy group. L represents a monoanionic ligand.

[0066] The organometallic complex shown in this embodiment is an organometallic complex having a structure represented by the following general formula (G4).

[0067] [ka]

[0068] Note that in the general formula (G4), A r This represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 ~R 6 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. L represents a monoanionic ligand.

[0069] Examples of monoanionic ligands in each of the above configurations include monoanionic bidentate chelate ligands having a β-diketone structure, monoanionic bidentate chelate ligands having a carboxyl group, monoanionic bidentate chelate ligands having a phenolic hydroxyl group, monoanionic bidentate chelate ligands in which both coordinating elements are nitrogen, or aromatic heterocyclic bidentate ligands that form a metal-carbon bond with iridium through cyclometalation.

[0070] Furthermore, the monoanionic ligands mentioned above can be any of the following general formulas (L1) to (L6).

[0071] [ka]

[0072] In general formulas (L1) to (L6), R 71 ~R 94 Each of these independently represents hydrogen, a substituted or unsubstituted C1-C10 alkyl group, a halogen group, a vinyl group, a substituted or unsubstituted C1-C10 haloalkyl group, a substituted or unsubstituted C1-C10 alkoxy group, or a substituted or unsubstituted C1-C10 alkylthio group. 1 ~A 3 Each of these atoms independently bonds with either nitrogen or hydrogen, forming sp² atoms. 2 hybridized carbon or substituent sp 2 The compound carbon represents a C1-C6 alkyl group, a halogen group, a C1-C6 haloalkyl group, or a phenyl group, B 1 ~B 8 Each of these atoms independently bonds with either nitrogen or hydrogen, forming sp² atoms. 2 hybridized carbon or substituent sp 2 It represents a hybrid carbon atom, and the substituent represents one of the following: an alkyl group having 1 to 6 carbon atoms, a halogen group, a haloalkyl group having 1 to 6 carbon atoms, or a phenyl group.

[0073] Furthermore, the organometallic complex shown in this embodiment is an organometallic complex represented by the following general formula (G5).

[0074] [Chemical formula]

[0075] In the general formula (G5), R 1 and R 2 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 to R 6 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, a halogen group, or a trifluoromethyl group. Also, R 7 to R 11 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms, or a cyano group, and at least one represents a cyano group. Also, R 71 to R 73 each independently represents any one of hydrogen, an alkyl group having 1 to 10 carbon atoms, a halogen group, a vinyl group, a haloalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkylthio group having 1 to 10 carbon atoms.

[0076] Also, the organometallic complex shown in this embodiment is an organometallic complex represented by the following general formula (G6).

[0077] [Chemical formula]

[0078] In the general formula (G6), R 1 and R 2 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 and R 5Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, a halogen group, or a trifluoromethyl group. Also, R 7 ~R 11 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms, or a cyano group, and at least one represents a cyano group. Also, R 71 ~R 73 Each independently represents any one of hydrogen, an alkyl group having 1 to 10 carbon atoms, a halogen group, a vinyl group, a haloalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkylthio group having 1 to 10 carbon atoms.

[0079] Further, the organometallic complex shown in this embodiment is an organometallic complex represented by the following general formula (G7).

[0080] [Chemical formula]

[0081] In the general formula (G7), R 1 and R 2 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 ~R 6 Each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, a halogen group, or a trifluoromethyl group. Also, R 7 ~R 11 Each independently represents any one of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms, or a cyano group, and at least one represents a cyano group.

[0082] Furthermore, the organometallic complex shown in this embodiment is an organometallic complex represented by the following general formula (G8).

[0083] [ka]

[0084] In addition, in the general formula (G8), R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Also, R 3 and R 5 Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. 7 ~R 11 Each of these independently represents one of the following: hydrogen, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, a substituted or unsubstituted C3-C12 heteroaryl group, or a cyano group, with at least one representing a cyano group.

[0085] In addition, if any of the above general formulas (G1) to (G8) have substituents of a substituted or unsubstituted C6-C13 aryl group, or a substituted or unsubstituted C3-C12 heteroaryl group, the substituents may include C1-C6 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and hexyl groups, or C5-C7 cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, 1-norbornyl, and 2-norbornyl groups, or C6-C12 aryl groups such as phenyl and biphenyl groups.

[0086] Also, R in the above general formulas (G1) to (G8) 1 ~R 11Specific examples of C1-C6 alkyl groups in any of the groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, hexyl, isohexyl, sec-hexyl, tert-hexyl, neohexyl, 3-methylpentyl, 2-methylpentyl, 2-ethylbutyl, 1,2-dimethylbutyl, 2,3-dimethylbutyl, trifluoromethyl, and the like.

[0087] Also, R in the above general formulas (G5) to (G6) 71 ~R 73 Specific examples of alkyl groups having 1 to 10 carbon atoms in any of these groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, neohexyl group, 3-methylpentyl group, 2-methylpentyl group, 2-ethylbutyl group, 1,2-dimethylbutyl group, 2,3-dimethylbutyl group, 1-propylbutyl group, 1-propylpentyl group, 1-butylpentyl group, trifluoromethyl group, and the like.

[0088] Furthermore, R in the above general formulas (G2), (G4), (G5)~(G8) 3 ~R 11Specific examples of aryl groups having 6 to 13 carbon atoms in any of the above include phenyl groups, tolyl groups (o-tolyl, m-tolyl, p-tolyl), naphthyl groups (1-naphthyl, 2-naphthyl), biphenyl groups (biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl), xylyl groups, pentarenyl groups, indenyl groups, fluorenyl groups, phenanthryl groups, etc. It should be noted that the above substituents may bond to each other to form a ring. An example of this is when the carbon atom at position 9 of a fluorenyl group has two phenyl groups as substituents, and these phenyl groups bond to each other to form a spirofluorene skeleton.

[0089] Also, R in the above general formulas (G5) to (G8) 7 ~R 11 Specific examples of heteroaryl groups having 3 to 12 carbon atoms in any of these groups include imidazolyl, pyrazolyl, pyridyl, pyridazyl, triazyl, benzimidazolyl, and quinolyl groups.

[0090] Furthermore, R in the above general formulas (L1), (G5), and (G6) 71 ~R 73 Specific examples of halogen groups, vinyl groups, C1-C10 haloalkyl groups, C1-C10 alkoxy groups, or C1-C10 alkylthio groups in any of these include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, n-pentyloxy, isopentyloxy, sec-pentyloxy, tert-pentyloxy, neopentyloxy, n Examples include -hexyloxy group, isohexyloxy group, sec-hexyloxy group, tert-hexyloxy group, neohexyloxy group, cyclohexyloxy group, 3-methylpentyloxy group, 2-methylpentyloxy group, 2-ethylbutoxy group, 1,2-dimethylbutoxy group, 2,3-dimethylbutoxy group, 1-propylbutyl group, 1-propylpentyl group, 1-butylpentyl group, cyano group, fluorine, chlorine, bromine, iodine, trifluoromethyl group, etc.

[0091] Furthermore, it is preferable that at least one substituent of the aryl group bonded to the 5-position of the pyrazine skeleton has a cyano group. For example, in the organometallic complexes shown in general formulas (G5) to (G8), R 7 ~R 11 It is preferable that at least one of them has a cyano group.

[0092] Having a cyano group as at least one substituent on the aryl group bonded to the 5th position of the pyrazine skeleton improves resistance to decomposition during sublimation. On the other hand, the presence of a cyano group tends to shift the emission wavelength to the longer wavelength side, and especially when a pyrazine skeleton is present, the emission color tends to become a deep red. A deep red emission color tends to result in low current efficiency. Therefore, hydrogen, alkyl, or alkoxy groups are independently provided as substituents at the 3rd and 6th positions of the pyrazine skeleton, respectively.

[0093] Furthermore, by independently adding hydrogen, alkyl, or alkoxy groups as substituents at positions 3 and 6 of the pyrazine skeleton, the emission wavelength is shifted to shorter wavelengths compared to the case where an aryl group is present at at least one of positions 3 and 6 of the pyrazine skeleton. As a result, emission at longer wavelengths, which has poor luminescence, is reduced, and current efficiency can be improved. In addition, the sublimation temperature is lower than when an aryl group is present at at least one of positions 3 and 6 of the pyrazine skeleton.

[0094] Accordingly, one embodiment of the present invention is characterized in that the organometallic complex has, independently, one of hydrogen, an alkyl group, or an alkoxy group as a substituent at the 3rd and 6th positions of the pyrazine skeleton in general formulas (G1) to (G8), and at least one of the substituents of the aryl group bonded to the 5th position of the pyrazine skeleton is a cyano group.

[0095] In addition, in the above general formulas (G1) to (G8), the aryl group bonded to the 5-position of the pyrazine skeleton may be an alkyl group as well as a cyano group. Therefore, in the above general formulas (G5) to (G8), R 7 ~R 11At least one of them may be an alkyl group having 1 to 6 carbon atoms. In particular, R 7 or R 11 By having at least one of the elements be an alkyl group having 1 to 6 carbon atoms, the peak of the emission spectrum is prevented from shifting to the longer wavelength side, thus maintaining luminosity. In other words, in an organometallic complex according to one aspect of the present invention, a deep red color with high color purity and high efficiency can be obtained.

[0096] Next, a specific structural formula of an organometallic complex, which is one aspect of the present invention as described above, is shown below. However, the present invention is not limited to these.

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] The organometallic complexes represented by structural formulas (100) to (137) above are novel materials capable of phosphorescence emission. While these materials may have geometric and stereoisomers depending on the type of ligand, the organometallic complexes in one aspect of the present invention include all of these isomers.

[0103] Next, an example of a method for synthesizing an organometallic complex having a structure represented by general formula (G3), which is one aspect of the present invention, will be described.

[0104] ≪Synthesis method for pyrazine derivatives represented by general formula (G0)≫ The pyrazine derivative represented by the following general formula (G0), used in the synthesis of general formula (G3), can be synthesized by the synthesis method shown in the following synthesis scheme (A).

[0105] [ka]

[0106] In general formula (G0), A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. r This represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

[0107] For example, a pyrazine derivative represented by general formula (G0) can be obtained by coupling a pyrazine compound (A-1) with a boronic acid (A-2) to obtain intermediate (A-3), as shown in synthesis scheme (A). Subsequently, the derivative (G0) can be obtained by coupling intermediate (A-3) with a boronic acid (A-4). Note that boronic acid may be a boronic acid ester or a cyclic triol borate salt, etc.

[0108] [ka]

[0109] In the above synthesis scheme (A), X represents a halogen or triflate, and A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. rThis represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

[0110] Furthermore, since various types of the aforementioned compounds (A-1), (A-2), (A-3), and (A-4) are commercially available or can be synthesized, a large number of pyrazine derivatives represented by the general formula (G0) can be synthesized. Therefore, organometallic complexes, which are one embodiment of the present invention, are characterized by a wide variety of ligands.

[0111] ≪Method for synthesizing an organometallic complex according to one embodiment of the present invention, represented by general formula (G3)≫ An organometallic complex, one embodiment of the present invention represented by general formula (G3), can be obtained as shown in the synthesis scheme (B-1) below. This is achieved by heating a pyrazine derivative represented by general formula (G0) and a halogen-containing iridium compound (such as iridium chloride, iridium bromide, or iridium iodide) in an inert gas atmosphere using no solvent, or an alcohol-based solvent (such as glycerol, ethylene glycol, 2-methoxyethanol, or 2-ethoxyethanol) alone, or a mixed solvent of one or more alcohol-based solvents and water, to obtain a novel dinuclear complex (B) which is a type of organometallic complex having a halogen-bridged structure. The heating method is not particularly limited, and an oil bath, sand bath, or aluminum block may be used. Microwaves can also be used as a heating method.

[0112] [ka]

[0113] In the synthesis scheme (B-1), X represents a halogen, and A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. rThis represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

[0114] Furthermore, as shown in the synthesis scheme (B-2) below, by reacting the dinuclear complex (B) obtained in the above-described synthesis scheme (B-1) with the monoanionic ligand starting material HL in an inert gas atmosphere, the proton of HL is removed, and L, which is formed, coordinates to the central metal iridium, thereby obtaining an organometallic complex that is one embodiment of the present invention represented by general formula (G3). There are no particular limitations on the heating method, and an oil bath, sand bath, or aluminum block may be used. Microwaves can also be used as a heating method.

[0115] [ka]

[0116] In the synthesis scheme (B-2), L represents a monoanionic ligand, and A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. r This represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. Also, R 1 and R 2 Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

[0117] The above describes one example of a method for synthesizing organometallic complexes according to one aspect of the present invention. However, the present invention is not limited thereto, and the complexes may be synthesized by any other method.

[0118] Furthermore, since the organometallic complexes described above are capable of phosphorescence, they can be used as light-emitting materials or light-emitting substances for light-emitting devices.

[0119] Furthermore, by using an organometallic complex according to one aspect of the present invention, it is possible to realize a light-emitting device, light-emitting apparatus, electronic device, or lighting apparatus with high luminous efficiency. In addition, it is possible to realize a light-emitting device, light-emitting apparatus, electronic device, or lighting apparatus with low power consumption.

[0120] In this embodiment, one aspect of the present invention has been described. Furthermore, in other embodiments, another aspect of the present invention will be described. However, the aspects of the present invention are not limited to these. In other words, since various aspects of the invention are described in this embodiment and other embodiments, the aspects of the present invention are not limited to a specific aspect. For example, an example of application to a light-emitting device was shown as one aspect of the present invention, but the aspects of the present invention are not limited to this. Also, depending on the situation, one aspect of the present invention may be applied to something other than a light-emitting device.

[0121] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0122] (Embodiment 2) This embodiment describes a light-emitting device according to one aspect of the present invention.

[0123] Figure 1A shows a diagram representing a light-emitting device according to one embodiment of the present invention. The light-emitting device according to one embodiment of the present invention has a first electrode 181, a second electrode 182, and an EL layer 183. The EL layer 183 has the organic compound shown in Embodiment 1.

[0124] The EL layer 183 has a light-emitting layer 193, which contains a light-emitting material. A hole injection layer 191 and a hole transport layer 192 are provided between the light-emitting layer 193 and the first electrode 181. The organometallic complex described in Embodiment 1 is preferably used as a light-emitting material because it efficiently emits red phosphorescence.

[0125] Furthermore, the light-emitting layer 193 may contain a host material along with the light-emitting material. The host material is an organic compound having carrier transport properties. The host material may contain not just one type, but multiple types. In this case, it is preferable that the multiple organic compounds include an organic compound having electron transport properties and an organic compound having hole transport properties, as this allows for balancing the carriers within the light-emitting layer 193. Alternatively, the multiple organic compounds may all be organic compounds with electron transport properties, but their differing electron transport properties can be used to adjust the electron transport properties in the light-emitting layer 193. By appropriately adjusting the carrier balance, it is possible to provide a light-emitting device with a good lifetime. Furthermore, the configuration may involve forming excitation complexes between multiple organic compounds that constitute the host material, or between the host material and the light-emitting material. By forming excitation complexes with appropriate emission wavelengths, effective energy transfer to the light-emitting material can be achieved, providing a light-emitting device with high efficiency and a good lifetime.

[0126] In Figure 1A, the EL layer 183 is shown to include an emissive layer 193, a hole injection layer 191, and a hole transport layer 192, as well as electron transport layers 194 and 195. However, the configuration of the light-emitting device is not limited to these. None of these layers may be formed, or layers with other functions may be included.

[0127] Next, a detailed description of the structure and materials of the light-emitting device described above will be given. In one embodiment of the present invention, as described above, the light-emitting device has an EL layer 183 consisting of multiple layers between a pair of electrodes, a first electrode 181 and a second electrode 182, and any portion of the EL layer 183 contains the organic compound disclosed in Embodiment 1.

[0128] The first electrode 181 is preferably formed using a metal, alloy, conductive compound, or mixture thereof with a large work function (specifically, 4.0 eV or more). Specifically, examples include indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, and indium oxide (IWZO) containing tungsten oxide and zinc oxide. These conductive metal oxide films are usually deposited by sputtering, but they may also be fabricated using methods such as the sol-gel method. As an example of a fabrication method, indium zinc oxide can be formed by sputtering using a target containing 1 to 20 wt% zinc oxide relative to indium oxide. Indium oxide (IWZO) containing tungsten oxide and zinc oxide can also be formed by sputtering using a target containing 0.5 to 5 wt% tungsten oxide and 0.1 to 1 wt% zinc oxide relative to indium oxide. Other materials include gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride). Graphene can also be used. Furthermore, by using the composite material described later in the layer in contact with the first electrode 181 in the EL layer 183, the electrode material can be selected regardless of the work function.

[0129] The EL layer 183 preferably has a multilayer structure, but there are no particular limitations on the multilayer structure, and various layer structures such as hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, carrier block layer, exciton block layer, and charge generation layer can be applied. In this embodiment, two types of configurations will be described: one having a hole injection layer 191, a hole transport layer 192, a light-emitting layer 193, an electron transport layer 194, and an electron transport layer 195, as shown in Figure 1A, and another having a hole injection layer 191, a hole transport layer 192, a light-emitting layer 193, an electron transport layer 194, and a charge generation layer 196, as shown in Figure 1B. The materials constituting each layer are specifically described below.

[0130] The hole injection layer 191 is a layer containing an acceptor substance. Both organic and inorganic compounds can be used as the acceptor substance.

[0131] Examples of substances with acceptor properties include compounds having electron-withdrawing groups (halogen groups or cyano groups), such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated as F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile. In particular, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple heteroatoms, such as HAT-CN, are thermally stable and preferred. Furthermore, radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group) are preferred because they have very high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropanetriylidenates[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenates[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenates[2,3,4,5,6-pentafluorobenzeneacetonitrile]. In addition to the organic compounds mentioned above, other substances with acceptor properties that can be used include molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, or manganese oxide. Furthermore, the hole injection layer 191 can also be formed by phthalocyanine-based complex compounds such as phthalocyanine (abbreviated as H2Pc) or copper phthalocyanine (CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB) and N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviated as DNTPD), or polymers such as poly(3,4-ethylenedioxythiophene) / poly(styrene sulfonic acid) (PEDOT / PSS).Acceptor materials can extract electrons from adjacent hole transport layers (or hole transport materials) by applying an electric field.

[0132] Furthermore, a composite material containing the above-mentioned acceptor substance in a hole-transporting material can also be used as the hole injection layer 191. By using a composite material containing the acceptor substance in a hole-transporting material, it is possible to select the material for forming the electrode regardless of the work function. In other words, not only materials with a large work function but also materials with a small work function can be used as the first electrode 181.

[0133] Various organic compounds can be used as hole-transporting materials in composite materials, including aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.). -6 cm 2 It is preferable that the material has a hole mobility of / Vs or higher. Below, we specifically list organic compounds that can be used as hole transporting materials in composite materials.

[0134] Aromatic amine compounds that can be used in composite materials include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated as DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviated as DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated as DPA3B). Specifically, carbazole derivatives include 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole Lubazole (abbreviated as PCzPCN1), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated as TCPB), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated as CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, etc. can be used.Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert- Examples include butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, and 2,5,8,11-tetra(tert-butyl)perylene. In addition, pentacene, coronene, and the like can also be used. It may have a vinyl skeleton. Examples of aromatic hydrocarbons having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviated as DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated as DPVPA).

[0135] Furthermore, polymer compounds such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD) can also be used.

[0136] The hole-transporting material used in the composite material is more preferably one of the following: a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, it may be an aromatic amine having substituents including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. Furthermore, it is preferable that the second organic compound is a substance having an N,N-bis(4-biphenyl)amino group, as this allows for the creation of light-emitting devices with a good lifetime. Specifically, the second organic compounds mentioned above include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), and 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8 -yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d] 4-Fran-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation :BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-Diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-Diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-Diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-Diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'- Binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenyl Luamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-diphenyl-4'-(2-naphthyl)-4''-{9-(4-biphenylyl)carbazole)}triphenylamine N (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(4-biphenylyl)-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(1,1'-biphenyl-4-yl)-9,9'-spirobio[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spiro-bi[9H-fluoren]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(dibenzofuran-4-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4- Phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine Rubazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation Examples include PCBBiF, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio[9H-fluoren]-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio[9H-fluoren]-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio[9H-fluoren]-2-amine, and N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio[9H-fluoren]-1-amine.

[0137] Furthermore, it is even more preferable that the hole-transporting material used in the composite material has a relatively deep HOMO level between -5.7 eV and -5.4 eV. Having a relatively deep HOMO level in the hole-transporting material used in the composite material facilitates the injection of holes into the hole transport layer 192 and makes it easier to obtain a light-emitting device with a good lifetime.

[0138] Furthermore, by mixing alkali metal or alkaline earth metal fluoride into the above composite material (preferably with an atomic ratio of fluorine atoms of 20% or more in the layer), the refractive index of the layer can be reduced. This also allows for the formation of a layer with a low refractive index inside the EL layer 183, thereby improving the external quantum efficiency of the light-emitting device.

[0139] By forming the hole injection layer 191, the hole injection performance is improved, making it possible to obtain a light-emitting device with a low driving voltage. Furthermore, organic compounds with acceptor properties are easy to deposit and form films with, making them easy to use materials.

[0140] The hole transport layer 192 is formed by including a material having hole transport properties. The material having hole transport properties is 1 × 10 -6 cm 2It is preferable to have a hole mobility of / Vs or higher. Examples of materials having the above hole transport properties include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviated as BSPB), and 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPA). FLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCB ANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), etc., which have aromatic amine skeletons. Compounds such as 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), or compounds having a carbazole skeleton, or 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviated as DBT3P-II), 2,Examples include compounds having a thiophene skeleton such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), or compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Furthermore, the materials listed as having hole-transporting properties used in the composite material of the hole injection layer 191 can also be suitably used as materials constituting the hole transport layer 192.

[0141] The light-emitting layer 193 contains a light-emitting substance and a host material. The light-emitting layer 193 may also contain other materials. Furthermore, it may be a laminate of two layers with different compositions.

[0142] The luminescent material can be a fluorescent material, a phosphorescent material, a thermally activated delayed fluorescence (TADF) material, or any other luminescent material.

[0143] In the light-emitting layer 193, materials that can be used as fluorescent light-emitting substances include, for example, 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-antryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyren-1,6-diamine (abbreviation: 1,6FLPAPrn), and N,N'-bis(3-methylphenyl) N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (Abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (Abbreviation: PCAPA), perylene, 2,5,8,11-tetra(tert-butyl)perylene (Abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (Abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N',N'-triphenyl-1,4- Phenylenediamine (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N', N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubren, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetra Sen (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphen Nyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluorantene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-(pyran-4-ylidene) Examples include len-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), and 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). In particular, condensed aromatic diamine compounds, such as pyrenediamine compounds like 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred because they exhibit high hole-trapping properties and excellent luminescence efficiency and reliability. Other fluorescent materials can also be used.

[0144] When a phosphorescent material is used as the light-emitting material in the light-emitting layer 193, possible materials that can be used include, for example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazole-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), and tris[4-(3-biphenyl)-5- Organometallic iridium complexes having a 4H-triazole skeleton, such as sopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]), or tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1 Organometallic iridium complexes having a 1H-triazole skeleton such as -Me)3]), or organometallic iridium complexes having an imidazole skeleton such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenantridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), or bis[2-(4', 6'-Difluorophenyl)pyridinate-N,C2']Iridium(III)tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-Difluorophenyl)pyridinate-N,C2']Iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-Bis(trifluoromethyl)phenyl]pyridinate-N,C2'}Iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-Difluorophenyl)pyridinate-N,Examples include organometallic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups, such as [C2']iridium(III) acetylacetonate (abbreviated as FIracac), as ligands. These compounds exhibit blue phosphorescence and have emission wavelength peaks between 440 nm and 520 nm.

[0145] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) Pyrimidines such as (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]), and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]). Organometallic iridium complexes having a skeleton, or organometallic iridium complexes having a pyrazine skeleton such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), or tris(2-phenylpyridinato-N,C2')iridium(III) (abbreviation: [ Ir(ppy)3), bis(2-phenylpyridinato-N,C2')iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C2')iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C2') Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-(2-pyridinyl-κN)benzofloxacin [2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κ]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mbfpypy-d3)]), [2-d3-methyl-(2-pyridinyl-κN)be Examples include organometallic iridium complexes with a pyridine skeleton, such as [2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviated as [Ir(ppy)2(mbfpypy-d3)]), and rare earth metal complexes, such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]). These compounds mainly exhibit green phosphorescence and have an emission wavelength peak between 500 nm and 600 nm. Organometallic iridium complexes with a pyrimidine skeleton are particularly preferred due to their outstanding reliability and luminescence efficiency.

[0146] Also, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipvaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di(naphthalene-1-yl)pyrimidinato](dipvaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2( Organometallic iridium complexes having a pyrimidine skeleton such as (dpm)), or (acetylacetonato)bis(2,3,5-triphenylpyradinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyradinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) Organometallic iridium complexes having a pyrazine skeleton, such as (abbreviation: [Ir(Fdpq)2(acac)]), or organometallic iridium complexes having a pyridine skeleton, such as tris(1-phenylisoquinolinato-N,C2')iridium(III) (abbreviation: [Ir(piq)3]) and bis(1-phenylisoquinolinato-N,C2')iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), as well as 2,3,7,8,12,13,17,18-oc Examples include platinum complexes such as taethyl-21H,23H-porphyrin platinum(II) (abbreviated as PtOEP), or rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-tenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviated as [Eu(TTA)3(Phen)]). These compounds exhibit red phosphorescence and have an emission peak between 600 nm and 700 nm. Furthermore, organometallic iridium complexes with a pyrazine skeleton yield red emission with good chromaticity.Furthermore, the organometallic complex of one embodiment of the present invention described in Embodiment 1 is also a substance that exhibits good chromaticity and highly efficient red light emission.

[0147] The organometallic complex described in Embodiment 1 can also be used as a phosphorescent material. In one embodiment of the present invention, it is preferable that the light-emitting device uses the metal complex described in Embodiment 1. By using the organometallic complex described in Embodiment 1, a light-emitting device with good current efficiency and color purity can be provided.

[0148] In addition to the phosphorescent compounds described above, other known phosphorescent substances may be selected and used.

[0149] As TADF materials, fullerenes and their derivatives, acridines and their derivatives, eosin derivatives, etc., can be used. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can be used. Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complexes (SnF2(Proto IX)), mesoporphyrin-tin fluoride complexes (SnF2(Meso IX)), hematoporphyrin-tin fluoride complexes (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complexes (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complexes (SnF2(OEP)), etioporphyrin-tin fluoride complexes (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complexes (PtCl2OEP), as shown in the following structural formulas.

[0150] [ka]

[0151] Furthermore, the following structural formulas represent 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviated as PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazine-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as PCCzPTzn), and 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine Heterocyclic compounds having one or both of a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring can also be used, such as PXZ-TRZ, 3-[4-(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (PPZ-3TPT), 3-(9,9-dimethyl-9H-acridine-10-yl)-9H-xanthene-9-one (ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (ACRSA). The heterocyclic compound is preferred because it has both a π-electron-excess heteroaromatic ring and a π-electron-deficient heteroaromatic ring, resulting in high electron transport and hole transport properties. Among the skeletons having a π-electron-deficient heteroaromatic ring, the pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, the benzoflopyrimidine skeleton, benzothienopyrimidine skeleton, benzoflopyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptor properties and are reliable. Furthermore, among the skeletons having a π-electron-excess heteroaromatic ring, the acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable, and therefore it is preferable to have at least one of these skeletons.Furthermore, a dibenzofuran skeleton is preferred as the furan skeleton, and a dibenzothiophene skeleton is preferred as the thiophene skeleton. In addition, as the pyrrole skeleton, indole skeleton, carbazole skeleton, indrocarbazole skeleton, bicarbazole skeleton, and 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeleton are particularly preferred. Substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded are particularly preferred because both the electron-donating and electron-accepting properties of the π-electron-rich heteroaromatic ring are strengthened, and the energy difference between the S1 and T1 levels is reduced, thus efficiently obtaining thermally activated delayed fluorescence. In addition, an aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may be used instead of the π-electron-deficient heteroaromatic ring. Furthermore, aromatic amine skeletons, phenazine skeletons, etc., can be used as the π-electron-rich skeleton. Furthermore, as π-electron-deficient skeletons, xanthene skeletons, thioxanthene dioxide skeletons, oxadiazole skeletons, triazole skeletons, imidazole skeletons, anthraquinone skeletons, boron-containing skeletons such as phenylborane or volanthrene, nitrile groups such as benzonitrile or cyanobenzene, aromatic rings or heteroaromatic rings having cyano groups, carbonyl skeletons such as benzophenone, phosphine oxide skeletons, sulfone skeletons, etc., can be used. In this way, π-electron-deficient skeletons and π-electron-excess skeletons can be used instead of at least one of π-electron-deficient heteroaromatic rings and π-electron-excess heteroaromatic rings.

[0152] [ka]

[0153] TADF materials are materials that have a small difference between the S1 and T1 energy levels and possess the ability to convert energy from triplet excitation energy to singlet excitation energy through reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy with only a small amount of thermal energy (reverse intersystem crossing), and singlet excited states can be efficiently generated. Furthermore, triplet excitation energy can be converted into luminescence.

[0154] Furthermore, an excited complex (also called an exciplex) that forms an excited state with two types of substances has an extremely small difference between the S1 and T1 levels and functions as a TADF material that can convert triplet excitation energy into singlet excitation energy.

[0155] Furthermore, the phosphorescence spectrum observed at low temperatures (e.g., 77K to 10K) can be used as an indicator of the T1 level. For TADF materials, when a tangent is drawn at the short-wavelength tail of the fluorescence spectrum and the energy at the wavelength of the extrapolation is taken as the S1 level, and when a tangent is drawn at the short-wavelength tail of the phosphorescence spectrum and the energy at the wavelength of the extrapolation is taken as the T1 level, it is preferable that the difference between S1 and T1 is 0.3 eV or less, and more preferably 0.2 eV or less.

[0156] Furthermore, when using TADF material as a light-emitting material, it is preferable that the S1 level of the host material is higher than the S1 level of the TADF material. Also, it is preferable that the T1 level of the host material is higher than the T1 level of the TADF material.

[0157] Various carrier transport materials can be used as the host material for the light-emitting layer, such as materials with electron transport properties, materials with hole transport properties, or the TADF material mentioned above.

[0158] As materials having hole transport properties, organic compounds having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton are preferred. For example, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPAFLP), 4- Phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB) Aromatic amine skeletons such as 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF). Compounds having the carbazole skeleton, such as 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviated as DBT3P-II), 2,Examples include compounds having a thiophene skeleton such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage.

[0159] Preferred materials with electron transport properties include metal complexes such as bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviated as BAlq), bis(8-quinolinolato)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazollyl)phenolato]zinc(II) (abbreviated as ZnPBO), and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviated as ZnBTZ), or organic compounds having a π-electron-deficient heteroaromatic ring skeleton. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), and 2-[3-(dibenzothiophen-4-yl)phenyl Heterocyclic compounds having a polyazole skeleton such as ]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBT BPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,Heterocyclic compounds having a diazine skeleton such as 8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 2-[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobio(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo"b"naphtho[1,2-d]furan- Examples include heterocyclic compounds having a triazine skeleton, such as 8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn) and 2-{3-[3-(benzo"b"naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), and heterocyclic compounds having a pyridine skeleton, such as 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB). Among the above, heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a triazine skeleton, and heterocyclic compounds having a pyridine skeleton are preferred due to their good reliability. In particular, heterocyclic compounds with a diazine (pyrimidine or pyrazine) skeleton exhibit high electron transport properties and contribute to reducing the driving voltage.

[0160] The TADF materials listed above can be used as host materials. When a TADF material is used as a host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing, and this energy is then transferred to the light-emitting material, thereby increasing the luminescence efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor.

[0161] This is particularly effective when the light-emitting material is a fluorescent material. Furthermore, in order to obtain high luminescence efficiency, it is preferable that the S1 level of the TADF material is higher than that of the fluorescent material. Also, it is preferable that the T1 level of the TADF material is higher than that of the fluorescent material. Therefore, it is preferable that the T1 level of the TADF material is higher than that of the fluorescent material.

[0162] Furthermore, it is preferable to use a TADF material that exhibits emission that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material. This is preferable because it allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient emission.

[0163] Furthermore, for singlet excitation energy to be efficiently generated from triplet excitation energy by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. It is also preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. To achieve this, it is preferable that the fluorescent material has protecting groups around the luminescent phosphoform (the skeleton that causes luminescence). Preferred protecting groups are substituents without π bonds, saturated hydrocarbons, specifically alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, and trialkylsilyl groups having 3 to 10 carbon atoms. It is even preferable to have multiple protecting groups. Substituents without π bonds have poor carrier transport function, and therefore can increase the distance between the TADF material and the luminescent phosphoform of the fluorescent material with little effect on carrier transport and carrier recombination. Here, the luminescent phosphoform refers to the atomic group (skeleton) that causes luminescence in the fluorescent material. The luminescent phosphodiosity preferably has a skeleton containing π bonds, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of condensed aromatic rings or condensed heteroaromatic rings include phenanthrene skeletons, stilbene skeletons, acridone skeletons, phenoxazine skeletons, and phenothiazine skeletons. Fluorescent materials having naphthalene, anthracene, fluorene, chrysene, triphenylene, tetracene, pyrene, perylene, coumarin, quinacridone, or naphthobisbenzofuran skeletons are particularly preferred due to their high fluorescence quantum yield.

[0164] When using a fluorescent material as the light-emitting material, a material having an anthracene skeleton is preferred as the host material. Using a material having an anthracene skeleton as the host material for a fluorescent material makes it possible to realize a light-emitting layer with good luminescence efficiency and durability. Among the materials having an anthracene skeleton to be used as the host material, materials having a diphenylanthracene skeleton, and especially a 9,10-diphenylanthracene skeleton, are preferred because they are chemically stable. Furthermore, while a carbazole skeleton is preferred as the host material because it improves hole injection and transport, a benzocarbazole skeleton, in which a benzene ring is further condensed into carbazole, is even more preferred because the HOMO is about 0.1 eV shallower than carbazole, making it easier for holes to enter. In particular, a dibenzocarbazole skeleton is preferred as the HOMO is about 0.1 eV shallower than carbazole, making it easier for holes to enter, and it also has excellent hole transport properties and high heat resistance. Therefore, a more preferable host material is a substance that simultaneously possesses a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or dibenzocarbazole skeleton). Furthermore, from the viewpoint of hole injection and transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton. Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviated as CzPA), and 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole. Examples include ruvasol (abbreviated as cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviated as 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}anthracene (abbreviated as FLPPA), and 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth).In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good characteristics and are therefore preferred choices.

[0165] The host material may be a mixture of multiple substances, and when using a mixed host material, it is preferable to mix an electron-transporting material with a hole-transporting material. By mixing an electron-transporting material with a hole-transporting material, the transport properties of the light-emitting layer 193 can be easily adjusted, and the recombination region can also be easily controlled. The weight ratio of the hole-transporting material to the electron-transporting material should be 1:19 to 19:1.

[0166] Furthermore, a phosphorescent material can be used as part of the above-mentioned mixed material. The phosphorescent material can be used as an energy donor to supply excitation energy to a fluorescent material when a fluorescent material is used as the light-emitting material. In addition, the organometallic complex described in Embodiment 1 can be used as the phosphorescent material.

[0167] Furthermore, these mixed materials may form an excited complex. It is preferable to select a combination that forms an excited complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the luminescent material, as this facilitates smooth energy transfer and efficiently obtains light emission. This configuration is also preferable because it reduces the driving voltage.

[0168] Furthermore, at least one of the materials forming the excitation complex may be a phosphorescent material. This allows for the efficient conversion of the triplet excitation energy to the singlet excitation energy through reverse intersystem crossing.

[0169] For efficient excitation complex formation, it is preferable that the HOMO level of the hole-transporting material is above the HOMO level of the electron-transporting material. Furthermore, it is preferable that the LUMO level of the hole-transporting material is above the LUMO level of the electron-transporting material. The LUMO and HOMO levels of the materials can be derived from the electrochemical properties (reduction potential and oxidation potential) of the materials measured by cyclic voltammetry (CV).

[0170] The formation of excited complexes can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, an electron-transporting material, and a mixed film made by mixing these materials, and observing that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectra of each individual material (or has a new peak on the longer wavelength side). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a mixed film made by mixing these materials, and observing differences in the transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component or a larger proportion of the delayed component than the transient PL lifetime of each individual material. Furthermore, the transient PL mentioned above can be replaced with transient electroluminescence (EL). That is, the formation of excited complexes can also be confirmed by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and the transient EL of a mixed film made by mixing these materials, and observing the differences in the transient response.

[0171] The electron transport layer 194 is a layer containing an electron-transporting material. As the electron-transporting material, any of the electron-transporting materials listed above as usable in the host material can be used.

[0172] Furthermore, the electron transport layer 194 has an electron mobility of 1 × 10⁻¹⁴ when the square root of the electric field strength [V / cm] is 600. -7 cm 2 / Vs or more 5×10 -5 cm 2It is preferable that the value is less than or equal to / Vs. By reducing the electron transport properties in the electron transport layer 194, the amount of electrons injected into the light-emitting layer can be controlled, preventing the light-emitting layer from becoming electron-excessive. Furthermore, it is preferable that the electron transport layer contains an electron-transporting material and an alkali metal or an alkali metal element, compound, or complex. These configurations are particularly preferable because they result in a good lifetime when the hole injection layer is formed as a composite material and the HOMO level of the hole-transporting material in the composite material is a relatively deep HOMO level between -5.7eV and -5.4eV. In this case, it is preferable that the HOMO level of the electron-transporting material is -6.0eV or higher. Furthermore, it is preferable that the electron-transporting material is an organic compound having an anthracene skeleton, and more preferably an organic compound containing both an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing five-membered ring skeleton or a nitrogen-containing six-membered ring skeleton. These heterocyclic skeletons are particularly preferably nitrogen-containing five-membered ring skeletons or nitrogen-containing six-membered ring skeletons that contain two heteroatoms in the ring, such as pyrazole rings, imidazole rings, oxazole rings, thiazole rings, pyrazine rings, pyrimidine rings, and pyridazine rings. Furthermore, the alkali metal or alkali metal element, compound, or complex preferably contains an 8-hydroxyquinolinate structure. Specifically, examples include 8-hydroxyquinolinate-lithium (abbreviated as Liq) and 8-hydroxyquinolinate-sodium (abbreviated as Naq). In particular, complexes of monovalent metal ions, especially lithium complexes, are preferred, with Liq being more preferred. When an 8-hydroxyquinolinate structure is included, its methyl-substituted derivatives (e.g., 2-methyl-substituted derivatives or 5-methyl-substituted derivatives) can also be used. Furthermore, it is preferable that alkali metals or alkali metal elements, compounds, or complexes exist in the electron transport layer with a concentration difference (including cases where the concentration is zero) in the thickness direction.

[0173] Between the electron transport layer 194 and the second electrode 182, an electron transport layer 195 may be provided, which contains an alkali metal or alkaline earth metal or a compound thereof, such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), or 8-hydroxyquinolinatolithium (abbreviated as Liq). The electron transport layer 195 may be a layer made of an electron-transporting material containing an alkali metal or alkaline earth metal or a compound thereof, or an electride may be used. Examples of electrides include a material obtained by adding electrons to a mixed oxide of calcium and aluminum at a high concentration.

[0174] Furthermore, as the electron transport layer 195, it is also possible to use a layer containing an alkali metal or alkaline earth metal fluoride in a concentration (50 wt% or more) that is in a microcrystalline state, in a material having electron transport properties (preferably an organic compound having a bipyridine skeleton). Since this layer has a low refractive index, it is possible to provide a light-emitting device with better external quantum efficiency.

[0175] Alternatively, a charge generation layer 196 may be provided instead of the electron transport layer 195 (Figure 1B). The charge generation layer 196 is a layer that can inject holes into the layer in contact with the cathode side and electrons into the layer in contact with the anode side by applying a potential. The charge generation layer 196 includes at least a P-type layer 197. The P-type layer 197 is preferably formed using a composite material listed above as a material that can constitute the hole injection layer 191. The P-type layer 197 may also be formed by laminating a film containing the acceptor material and a film containing the hole transport material as materials constituting the composite material. By applying a potential to the P-type layer 197, electrons are injected into the electron transport layer 194 and holes are injected into the second electrode 182, which is the cathode, and the light-emitting device operates. Furthermore, since the organic compound in one aspect of the present invention is an organic compound with a low refractive index, by using it in the P-type layer 197, a light-emitting device with good external quantum efficiency can be obtained.

[0176] In addition, it is preferable that the charge generation layer 196 has either or both of an electron relay layer 198 and an electron injection buffer layer 199 in addition to the P-type layer 197.

[0177] The electron relay layer 198 contains at least a substance having electron transporting properties and has a function of preventing the interaction between the electron injection buffer layer 199 and the P-type layer 197 and smoothly transferring electrons. The LUMO level of the substance having electron transporting properties contained in the electron relay layer 198 is preferably between the LUMO level of the acceptor substance in the P-type layer 197 and the LUMO level of the substance contained in the layer in contact with the charge generation layer 196 in the electron transport layer 194. The specific energy level of the LUMO level in the substance having electron transporting properties used for the electron relay layer 198 is preferably -5.0 eV or more, preferably -5.0 eV or more and -3.0 eV or less. In addition, as the substance having electron transporting properties used for the electron relay layer 198, it is preferable to use a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0178] For the electron injection buffer layer 199, it is possible to use substances with high electron injection properties such as alkali metals, alkaline earth metals, rare earth metals, and their compounds (including alkali metal compounds (oxides such as lithium oxide, halides, lithium carbonate, or carbonates such as cesium carbonate), alkaline earth metal compounds (including oxides, halides, carbonates), or rare earth metal compounds (including oxides, halides, carbonates)).

[0179] Furthermore, if the electron injection buffer layer 199 is formed by including an electron-transporting substance and a donor substance, the donor substance can include alkali metals, alkaline earth metals, rare earth metals, and compounds thereof (alkali metal compounds (including oxides, halides, lithium carbonate, or carbonates such as cesium carbonate), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metal compounds (including oxides, halides, and carbonates)), as well as organic compounds such as tetratianaphthalene (abbreviated as TTN), nickerosene, and decamethylnickerosene. The electron-transporting substance can be formed using the same materials as those used to constitute the electron transport layer 194 described earlier.

[0180] As the material forming the second electrode 182, metals, alloys, electrically conductive compounds, and mixtures thereof with a small work function (specifically, 3.8 eV or less) can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) and cesium (Cs), or elements belonging to Group 1 or 2 of the periodic table such as magnesium (Mg), calcium (Ca), and strontium (Sr), alloys containing these elements (MgAg, AlLi), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing these elements. However, by providing an electron injection layer between the second electrode 182 and the electron transport layer, various conductive materials such as Al, Ag, ITO, silicon, or indium oxide-tin oxide containing silicon oxide can be used as the second electrode 182, regardless of the magnitude of their work functions. These conductive materials can be deposited using dry methods such as vacuum deposition and sputtering, inkjet methods, and spin coating methods. Alternatively, the material may be formed using a wet process with a sol-gel method, or it may be formed using a wet process with a paste of a metallic material.

[0181] Furthermore, various methods can be used to form the EL layer 183, regardless of whether they are dry or wet methods. For example, vacuum deposition, gravure printing, offset printing, screen printing, inkjet printing, or spin coating may be used.

[0182] Furthermore, each electrode or layer described above may be formed using different film deposition methods.

[0183] The configuration of the layer provided between the first electrode 181 and the second electrode 182 is not limited to those described above. However, a configuration is preferred in which a light-emitting region is provided at a location away from the first electrode 181 and the second electrode 182 where holes and electrons recombine, in order to suppress quenching caused by the proximity of the light-emitting region to the electrode or the metal used in the carrier injection layer.

[0184] Furthermore, the hole transport layer and electron transport layer in contact with the light-emitting layer 193, and especially the carrier transport layer near the recombination region in the light-emitting layer 193, are preferably composed of a material whose band gap is larger than that of the light-emitting material constituting the light-emitting layer or the light-emitting material contained in the light-emitting layer, in order to suppress energy transfer from excitons generated in the light-emitting layer.

[0185] Next, an embodiment of a light-emitting device (also called a stacked element or tandem element) with a configuration in which multiple light-emitting units are stacked will be described with reference to Figure 1C. This light-emitting device has multiple light-emitting units between the anode and the cathode. Each light-emitting unit has a configuration almost identical to the EL layer 183 shown in Figure 1A. In other words, the light-emitting device shown in Figure 1C is a light-emitting device having multiple light-emitting units, while the light-emitting device shown in Figure 1A or Figure 1B is a light-emitting device having one light-emitting unit.

[0186] In Figure 1C, a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between the anode 501 and the cathode 502, and a charge generation layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The anode 501 and the cathode 502 correspond to the first electrode 181 and the second electrode 182 in Figure 1A, respectively, and the same components described in the explanation of Figure 1A can be applied. Furthermore, the first light-emitting unit 511 and the second light-emitting unit 512 may have the same configuration or different configurations.

[0187] The charge generation layer 513 has the function of injecting electrons into one light-emitting unit and holes into the other light-emitting unit when a voltage is applied to the anode 501 and cathode 502. That is, in Figure 1C, when a voltage is applied such that the potential of the anode is higher than the potential of the cathode, the charge generation layer 513 only needs to inject electrons into the first light-emitting unit 511 and holes into the second light-emitting unit 512.

[0188] The charge generation layer 513 is preferably formed with the same configuration as the charge generation layer 196 described in Figure 1B. The composite material of organic compound and metal oxide has excellent carrier implantation and carrier transport properties, enabling low-voltage and low-current operation. If the anode side of the light-emitting unit is in contact with the charge generation layer 513, the charge generation layer 513 can also act as a hole injection layer for the light-emitting unit, so the light-emitting unit does not need to have a hole injection layer.

[0189] Furthermore, when an electron injection buffer layer 199 is provided in the charge generation layer 513, the electron injection buffer layer 199 plays the role of an electron injection layer in the anode-side light-emitting unit, so it is not necessarily required to form an electron injection layer in the anode-side light-emitting unit.

[0190] Figure 1C illustrates a light-emitting device having two light-emitting units, but the same principles can be applied to light-emitting devices with three or more stacked light-emitting units. As in the light-emitting device according to this embodiment, by arranging multiple light-emitting units separated between a pair of electrodes by a charge generation layer 513, high-brightness light emission can be achieved while maintaining a low current density, and a longer-life element can be realized. Furthermore, a light-emitting device that can be driven at a low voltage and consumes little power can be realized.

[0191] Furthermore, by making the light-emitting colors of each light-emitting unit different, it is possible to obtain a desired color of light emission from the entire light-emitting device. For example, in a light-emitting device having two light-emitting units, it is possible to obtain a light-emitting device that emits white light as a whole by obtaining red and green light-emitting colors from the first light-emitting unit and blue light-emitting color from the second light-emitting unit.

[0192] Furthermore, each of the layers, such as the EL layer 183, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer, as well as the electrodes, can be formed using methods such as vapor deposition (including vacuum deposition), droplet ejection (also known as inkjet printing), coating, and gravure printing. They may also contain low-molecular-weight materials, medium-molecular-weight materials (including oligomers and dendrimers), or polymer materials.

[0193] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0194] (Embodiment 3) This embodiment describes a light-emitting device using the light-emitting device described in Embodiment 2.

[0195] In this embodiment, a light-emitting device fabricated using the light-emitting device described in Embodiment 2 will be explained with reference to Figure 2. Figure 2A is a top view showing the light-emitting device, and Figure 2B is a cross-sectional view obtained by cutting Figure 2A along AB and CD. This light-emitting device includes a drive circuit section (source line drive circuit) 601, a pixel section 602, and a drive circuit section (gate line drive circuit) 603, all indicated by dotted lines, to control the light emission of the light-emitting device. Furthermore, 604 is a sealing substrate, and 605 is a sealing material, with the area enclosed by the sealing material 605 being a space 607.

[0196] The routing wiring 608 is for transmitting signals input to the source line drive circuit 601 and the gate line drive circuit 603, and receives video signals, clock signals, start signals, reset signals, etc. from the FPC (flexible printed circuit) 609, which serves as an external input terminal. Although only the FPC is shown in this illustration, a printed circuit board (PWB) may be attached to this FPC. In this specification, the light-emitting device includes not only the light-emitting device itself, but also the state in which the FPC or PWB is attached to it.

[0197] Next, the cross-sectional structure will be explained using Figure 2B. A drive circuit section and a pixel section are formed on the element substrate 610, and here, the source line drive circuit 601, which is the drive circuit section, and one pixel in the pixel section 602 are shown.

[0198] The element substrate 610 may be manufactured using a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or other materials, as well as a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, or acrylic resin.

[0199] The structure of the transistors used in the pixels and the driving circuits is not particularly limited. For example, an inverted staggered transistor or a staggered transistor may be used. Also, a top gate transistor or a bottom gate transistor may be used. The semiconductor material used for the transistors is not particularly limited, and for example, silicon, germanium, silicon carbide, gallium nitride, etc. can be used. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In-Ga-Zn-based metal oxide, may be used.

[0200] The crystallinity of the semiconductor material used for the transistors is also not particularly limited, and any of an amorphous semiconductor, a semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single crystal semiconductor, or a semiconductor having a crystal region in part) may be used. Using a semiconductor having crystallinity is preferable because deterioration of transistor characteristics can be suppressed.

[0201] Here, in addition to the transistors provided in the above pixels and driving circuits, for semiconductor devices such as transistors used in touch sensors and the like described later, it is preferable to apply an oxide semiconductor. In particular, it is preferable to apply an oxide semiconductor having a wider band gap than silicon. By using an oxide semiconductor having a wider band gap than silicon, the current in the off state of the transistor can be reduced.

[0202] The above oxide semiconductor preferably contains at least indium (In) or zinc (Zn). Further, it is more preferable that it is an oxide semiconductor containing an oxide represented by an In-M-Zn-based oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce or Hf).

[0203] In particular, as the semiconductor layer, it is preferable to use an oxide semiconductor film having a plurality of crystal parts, wherein the c-axis of the crystal parts is oriented perpendicular to the surface to be formed of the semiconductor layer or the upper surface of the semiconductor layer, and there is no grain boundary between adjacent crystal parts.

[0204] By using such materials as semiconductor layers, fluctuations in electrical properties can be suppressed, enabling the realization of highly reliable transistors.

[0205] Furthermore, due to its low off-current, the transistor having the aforementioned semiconductor layer can retain the charge stored in the capacitor via the transistor for a long period of time. By applying such transistors to pixels, it becomes possible to maintain the gradation of the image displayed in each display area while simultaneously stopping the drive circuit. As a result, electronic devices with extremely reduced power consumption can be realized.

[0206] It is preferable to provide an undercoat to stabilize the characteristics of the transistor. As the undercoat, an inorganic insulating film such as a silicon oxide film, silicon nitride film, silicon oxynitride film, or silicon nitride film can be used and fabricated as a single layer or in layers. The undercoat can be formed using sputtering, CVD (Chemical Vapor Deposition) (plasma CVD, thermal CVD, MOCVD (Metal Organic CVD), etc.), ALD (Atomic Layer Deposition), coating, printing, etc. Note that the undercoat may be omitted if not necessary.

[0207] Note that FET623 is one of the transistors formed in the source line drive circuit 601. The drive circuit can be formed using various CMOS, PMOS, or NMOS circuits. In this embodiment, a driver-integrated type with the drive circuit formed on the substrate is shown, but this is not necessarily required, and the drive circuit can be formed externally instead of on the substrate.

[0208] Furthermore, although the pixel section 602 is formed by a plurality of pixels including a switching FET 611 and a current control FET 612 and a first electrode 613 electrically connected to its drain, it is not limited to this, and the pixel section may be a combination of three or more FETs and a capacitive element.

[0209] Furthermore, an insulator 614 is formed to cover the end of the first electrode 613. This can be formed by using a positive-type photosensitive acrylic resin film.

[0210] Furthermore, in order to ensure good coverage of the EL layer and the like that will be formed later, a curved surface with curvature is formed at the upper or lower end of the insulator 614. For example, when a positive-type photosensitive acrylic resin is used as the material for the insulator 614, it is preferable to have a curved surface with a radius of curvature (0.2 μm to 3 μm) only at the upper end of the insulator 614. In addition, either a negative-type photosensitive resin or a positive-type photosensitive resin can be used as the insulator 614.

[0211] An EL layer 616 and a second electrode 617 are formed on the first electrode 613, respectively. Here, it is desirable to use a material with a large work function for the first electrode 613 which functions as an anode. For example, in addition to single-layer films such as ITO film, silicon-containing indium tin oxide film, indium oxide film containing 2-20 wt% zinc oxide, titanium nitride film, chromium film, tungsten film, Zn film, and Pt film, a laminate of titanium nitride film and a film mainly composed of aluminum, or a three-layer structure of titanium nitride film, a film mainly composed of aluminum, and titanium nitride film can be used. Furthermore, a laminated structure has low resistance as wiring, good ohmic contact can be obtained, and it can function as an anode.

[0212] Furthermore, the EL layer 616 is formed by various methods such as vapor deposition using a vapor deposition mask, inkjet printing, and spin coating. The EL layer 616 includes the configuration described in Embodiment 2. Other materials constituting the EL layer 616 may be low molecular weight compounds or high molecular weight compounds (including oligomers and dendrimers).

[0213] Furthermore, it is preferable to use a material with a low work function (such as Al, Mg, Li, Ca, or alloys or compounds thereof (MgAg, MgIn, AlLi, etc.)) for the second electrode 617, which is formed on the EL layer 616 and functions as a cathode. When light generated in the EL layer 616 is transmitted through the second electrode 617, it is preferable to use a laminate of a thin metal film and a transparent conductive film (such as ITO, indium oxide containing 2-20 wt% zinc oxide, indium tin oxide containing silicon, or zinc oxide (ZnO)) as the second electrode 617.

[0214] The first electrode 613, the EL layer 616, and the second electrode 617 form a light-emitting device. This light-emitting device is the light-emitting device described in Embodiment 2. Although the pixel portion is made up of multiple light-emitting devices, the light-emitting device in this embodiment may contain a mixture of the light-emitting device described in Embodiment 2 and light-emitting devices having other configurations.

[0215] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, the light-emitting device 618 is provided in the space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The space 607 is filled with a filler material, which may be an inert gas (such as nitrogen or argon) or a sealing material. A recess is formed in the sealing substrate, and a desiccant is placed therein to suppress deterioration due to the effects of moisture, which is a preferred configuration.

[0216] Furthermore, it is preferable to use epoxy resin or glass frit for the sealing material 605. It is also desirable that these materials are as impermeable to moisture and oxygen as possible. In addition to glass substrates or quartz substrates, plastic substrates made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, or acrylic resin can be used as the material for the sealing substrate 604.

[0217] Although not shown in Figure 2, a protective film may be provided on the second electrode. The protective film may be formed of an organic resin film or an inorganic insulating film. Alternatively, the protective film may be formed to cover the exposed portion of the sealing material 605. Furthermore, the protective film can be provided to cover the surface and sides of the pair of substrates, the sealing layer, the insulating layer, and other exposed sides.

[0218] The protective film can be made of a material that is impermeable to impurities such as water. Therefore, it is possible to effectively suppress the diffusion of impurities such as water from the outside to the inside.

[0219] Materials that constitute the protective film can include oxides, nitrides, fluorides, sulfides, ternary compounds, metals, or polymers. For example, materials containing aluminum oxide, hafnium oxide, hafnium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide, titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide, or indium oxide can be used. Materials containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride can be used. Nitrides containing titanium and aluminum, oxides containing titanium and aluminum, oxides containing aluminum and zinc, sulfides containing manganese and zinc, sulfides containing cerium and strontium, oxides containing erbium and aluminum, oxides containing yttrium and zirconium can be used.

[0220] It is preferable to form the protective film using a film deposition method that provides good step coverage. One such method is atomic layer deposition (ALD). It is preferable to use a material that can be formed using the ALD method for the protective film. By using the ALD method, it is possible to form a dense protective film with reduced defects such as cracks and pinholes, or a protective film with a uniform thickness. Furthermore, it is possible to reduce the damage inflicted on the processed workpiece when forming the protective film.

[0221] For example, by using the ALD method to form a protective film, a uniform and defect-free protective film can be formed on surfaces with complex uneven shapes, including the top, sides, and back of touch panels.

[0222] As described above, a light-emitting device can be obtained using the light-emitting device described in Embodiment 2.

[0223] Since the light-emitting device in this embodiment uses the light-emitting device described in Embodiment 2, a light-emitting device with good characteristics can be obtained. Specifically, because the light-emitting device described in Embodiment 2 has good luminous efficiency, it is possible to make a light-emitting device with low power consumption.

[0224] Figure 3 shows an example of a light-emitting device that is made full-color by forming a light-emitting device that emits white light and providing a colored layer (color filter), etc. Figure 3A shows the substrate 1001, the underlayer insulating film 1002, the gate insulating film 1003, the gate electrodes 1006, 1007, 1008, the first interlayer insulating film 1020, the second interlayer insulating film 1021, the peripheral part 1042, the pixel part 1040, the drive circuit part 1041, the first electrodes 1024W, 1024R, 1024G, 1024B of the light-emitting device, the partition wall 1025, the EL layer 1028, the second electrode 1029 of the light-emitting device, the sealing substrate 1031, the sealing material 1032, etc.

[0225] In Figure 3A, the colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B) are provided on a transparent substrate 1033. A black matrix 1035 may also be provided. The transparent substrate 1033 on which the colored layers and black matrix are provided is aligned and fixed to the substrate 1001. The colored layers and black matrix 1035 are covered with an overcoat layer 1036. In Figure 3A, there is an emissive layer that emits light to the outside without passing through the colored layers, and an emissive layer that emits light to the outside by passing through each colored layer. Light that does not pass through the colored layers is white, and light that passes through the colored layers is red, green, and blue, so an image can be represented with four colored pixels.

[0226] Figure 3B shows an example in which colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B) are formed between the gate insulating film 1003 and the first interlayer insulating film 1020. Thus, the colored layers may also be provided between the substrate 1001 and the encapsulating substrate 1031.

[0227] Furthermore, although the light-emitting device described above is a bottom-emission type device that extracts light from the substrate 1001 on which the FET is formed, it may also be a top-emission type device that extracts light from the sealing substrate 1031. A cross-sectional view of the top-emission type light-emitting device is shown in Figure 4. In this case, the substrate 1001 can be a substrate that does not transmit light. The process is the same as for the bottom-emission type light-emitting device until the connecting electrode that connects the FET and the anode of the light-emitting device is fabricated. After that, a third interlayer insulating film 1037 is formed covering the electrode 1022. This insulating film may also play a planarization role. The third interlayer insulating film 1037 can be formed using the same material as the second interlayer insulating film, as well as other known materials.

[0228] The first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device are designated as anodes here, but they may also be cathodes. Furthermore, in the case of a top-emission type light-emitting device as shown in Figure 4, it is preferable that the first electrodes be reflective electrodes. The configuration of the EL layer 1028 is the same as that described as the EL layer 183 in Embodiment 2, and the element structure is such that white light emission can be obtained.

[0229] In the top emission structure shown in Figure 4, sealing can be performed with a sealing substrate 1031 having colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B). A black matrix 1035 may be provided on the sealing substrate 1031 so as to be located between pixels. The colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B) and the black matrix may be covered with an overcoat layer 1036. The sealing substrate 1031 should be a translucent substrate. In addition, although an example of full-color display using four colors, red, green, blue, and white, is shown here, it is not particularly limited, and full-color display may be performed using four colors, red, yellow, green, and blue, or three colors, red, green, and blue.

[0230] In top-emission type light-emitting devices, a microcavity structure can be suitably applied. A light-emitting device having a microcavity structure is obtained by using a reflective electrode as the first electrode and a semi-transparent / semi-reflective electrode as the second electrode. There is at least an EL layer between the reflective electrode and the semi-transparent / semi-reflective electrode, and there is at least a light-emitting layer that forms a light-emitting region.

[0231] The reflective electrode has a visible light reflectance of 40% to 100%, preferably 70% to 100%, and its resistivity is 1 × 10⁻⁶. -2 The film thickness is assumed to be Ωcm or less. Furthermore, the semi-transparent / semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%, and its resistivity is 1 × 10⁻⁶. -2 Assume the membrane is less than Ωcm in diameter.

[0232] The light emitted from the light-emitting layer contained in the EL layer is reflected by the reflective electrode and the semi-transparent / semi-reflective electrode, causing resonance.

[0233] This light-emitting device allows you to change the optical distance between the reflective electrode and the semi-transparent / semi-reflective electrode by changing the thickness of the transparent conductive film or the aforementioned composite material, carrier transport material, etc. This makes it possible to strengthen light of resonant wavelengths and attenuate light of non-resonant wavelengths between the reflective electrode and the semi-transparent / semi-reflective electrode.

[0234] Furthermore, since the light reflected back by the reflective electrode (first reflected light) interferes significantly with the light that directly enters the semi-transparent / semi-reflective electrode from the light-emitting layer (first incident light), it is preferable to adjust the optical distance between the reflective electrode and the light-emitting layer to (2n-1)λ / 4 (where n is a natural number greater than or equal to 1, and λ is the wavelength of the light emission to be amplified). By adjusting this optical distance, the phases of the first reflected light and the first incident light can be aligned, and the light emission from the light-emitting layer can be further amplified.

[0235] In the above configuration, the EL layer may have a structure with multiple light-emitting layers or a structure with a single light-emitting layer. For example, it may be applied to a configuration in which multiple EL layers are provided in a single light-emitting device with a charge generation layer in between, and one or more light-emitting layers are formed in each EL layer, in combination with the tandem light-emitting device configuration described above.

[0236] By incorporating a microcavity structure, it becomes possible to enhance the emission intensity in the front direction at specific wavelengths, thereby reducing power consumption. Furthermore, in the case of a light-emitting device that displays images using four sub-pixels of red, yellow, green, and blue, in addition to the brightness enhancement effect of yellow emission, a microcavity structure tailored to the wavelength of each color can be applied to all sub-pixels, resulting in a light-emitting device with excellent characteristics.

[0237] Since the light-emitting device in this embodiment uses the light-emitting device described in Embodiment 2, a light-emitting device with good characteristics can be obtained. Specifically, because the light-emitting device described in Embodiment 2 has good luminous efficiency, it is possible to make a light-emitting device with low power consumption.

[0238] Up to this point, we have described an active matrix type light-emitting device, but from here on we will describe a passive matrix type light-emitting device. Figure 5 shows a passive matrix type light-emitting device manufactured by applying the present invention. Figure 5A is a perspective view of the light-emitting device, and Figure 5B is a cross-sectional view of Figure 5A cut along the X and Y lines. In Figure 5, an EL layer 955 is provided on the substrate 951 between electrodes 952 and 956. The ends of electrodes 952 are covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The side walls of the partition layer 954 have a slope such that the distance between one side wall and the other side wall narrows as they get closer to the substrate surface. In other words, the cross-section of the partition layer 954 in the short-side direction is trapezoidal, with the bottom side (facing the same direction as the surface direction of the insulating layer 953 and in contact with the insulating layer 953) being shorter than the top side (facing the same direction as the surface direction of the insulating layer 953 and not in contact with the insulating layer 953). By providing the partition layer 954 in this way, it is possible to prevent malfunctions of the light-emitting device caused by static electricity, etc. Furthermore, even in a passive matrix type light-emitting device, the light-emitting device described in Embodiment 2 is used, resulting in a light-emitting device with good reliability or low power consumption.

[0239] As described above, the light-emitting device is suitable for use as a display device for representing images because it is possible to control each of the numerous minute light-emitting devices arranged in a matrix.

[0240] Furthermore, this embodiment can be freely combined with other embodiments.

[0241] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0242] (Embodiment 4) In this embodiment, an example of using the light-emitting device described in Embodiment 2 as an illumination device will be explained with reference to Figure 6. Figure 6A is a top view of the illumination device, and Figure 6B is a cross-sectional view of EF in Figure 6A.

[0243] In this embodiment, the lighting device has a first electrode 401 formed on a translucent substrate 400 which serves as a support. The first electrode 401 corresponds to the first electrode 181 in Embodiment 2. When light is extracted from the first electrode 401 side, the first electrode 401 is formed from a translucent material.

[0244] A pad 412 for supplying voltage to the second electrode 404 is formed on the substrate 400.

[0245] An EL layer 403 is formed on the first electrode 401. The EL layer 403 corresponds to the configuration of the EL layer 183 in Embodiment 2, or to a configuration combining the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer 513. Please refer to the relevant description for details on these configurations.

[0246] A second electrode 404 is formed by covering the EL layer 403. The second electrode 404 corresponds to the second electrode 182 in Embodiment 2. When light emission is extracted from the first electrode 401 side, the second electrode 404 is formed of a material with high reflectivity. Voltage is supplied to the second electrode 404 by connecting it to the pad 412.

[0247] As described above, the lighting device shown in this embodiment includes a light-emitting device having a first electrode 401, an EL layer 403, and a second electrode 404. Since this light-emitting device is a light-emitting device with high luminous efficiency, the lighting device in this embodiment can be a lighting device with low power consumption.

[0248] The lighting device is completed by fixing and sealing the substrate 400, on which the light-emitting device having the above configuration is formed, and the sealing substrate 407 using sealing materials 405 and 406. Either sealing material 405 or 406 may be used. In addition, a desiccant can be mixed into the inner sealing material 406 (not shown in Figure 6A), which allows for the adsorption of moisture and leads to improved reliability.

[0249] Furthermore, by extending the pad 412 and a portion of the first electrode 401 outside the sealing material 405 and sealing material 406, it can be used as an external input terminal. Alternatively, an IC chip 420 with a converter or the like may be provided on top of it.

[0250] As described above, the lighting device described in this embodiment uses the light-emitting device described in Embodiment 2 as the EL element, and can be a light-emitting device with low power consumption.

[0251] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0252] (Embodiment 5) This embodiment describes an example of an electronic device that includes the light-emitting device described in Embodiment 2 as part of it. The light-emitting device described in Embodiment 2 has good luminous efficiency and low power consumption. As a result, the electronic device described in this embodiment can be an electronic device having a light-emitting section with low power consumption.

[0253] Examples of electronic devices to which the above-mentioned light-emitting devices are applied include television equipment (also called televisions or television receivers), monitors for computers, digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable game consoles, personal digital assistants, sound playback devices, and large game machines such as pachinko machines. Specific examples of these electronic devices are shown below.

[0254] Figure 7A shows an example of a television system. The television system has a display unit 7103 incorporated into a housing 7101. This figure also shows a configuration in which the housing 7101 is supported by a stand 7105. The display unit 7103 is capable of displaying images, and the display unit 7103 is configured by arranging the light-emitting devices described in Embodiment 2 in a matrix.

[0255] The television system can be operated using the operation switches on the housing 7101 or a separate remote control unit 7110. The operation keys 7109 on the remote control unit 7110 allow for the operation of the television system's channels and volume, and the operation of the image displayed on the display unit 7103. Alternatively, the remote control unit 7110 may be configured to include a display unit 7107 that displays information output from the remote control unit 7110.

[0256] The television system shall consist of a receiver and a modem. The receiver will be able to receive general television broadcasts, and by connecting to a wired or wireless communication network via the modem, it will also be possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0257] Figure 7B1 shows a computer, which includes a main unit 7201, a housing 7202, a display unit 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, etc. This computer is manufactured by arranging the light-emitting devices described in Embodiment 2 in a matrix and using them for the display unit 7203. The computer in Figure 7B1 may also take the form shown in Figure 7B2. The computer in Figure 7B2 has a second display unit 7210 instead of the keyboard 7204 and pointing device 7206. The second display unit 7210 is a touch panel, and input can be performed by operating the input display shown on the second display unit 7210 with a finger or a dedicated pen. In addition to the input display, the second display unit 7210 can also display other images. The display unit 7203 may also be a touch panel. Because the two screens are connected by a hinge, it is possible to prevent problems such as scratching or damaging the screens when storing or transporting the device.

[0258] Figure 7C shows an example of a mobile terminal. The mobile terminal includes a display unit 7402 built into the housing 7401, as well as operation buttons 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like. The mobile terminal is equipped with a display unit 7402 made by arranging the light-emitting devices described in Embodiment 2 in a matrix.

[0259] The mobile terminal shown in Figure 7C can also be configured to allow information input by touching the display unit 7402 with a finger or other object. In this case, operations such as making a phone call or composing an email can be performed by touching the display unit 7402 with a finger or other object.

[0260] The display unit 7402 has three main modes. The first is a display mode that primarily displays images, the second is an input mode that primarily inputs information such as text, and the third is a display + input mode that combines the display mode and the input mode.

[0261] For example, when making a phone call or composing an email, the display unit 7402 should be set to a text input mode, which primarily focuses on text input, and the user should perform the text input operation displayed on the screen. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display unit 7402.

[0262] Furthermore, by providing a detection device with a tilt sensor such as a gyroscope or accelerometer inside the mobile terminal, the orientation of the mobile terminal (portrait or landscape) can be determined, and the screen display of the display unit 7402 can be automatically switched accordingly.

[0263] Furthermore, the screen mode can be switched by touching the display unit 7402 or by operating the operation button 7403 on the housing 7401. It is also possible to switch modes depending on the type of image displayed on the display unit 7402. For example, if the image signal displayed on the display unit is video data, it can be switched to display mode; if it is text data, it can be switched to input mode.

[0264] Furthermore, in input mode, the system may detect a signal detected by the optical sensor of the display unit 7402 and, if there is no input via touch operation on the display unit 7402 for a certain period of time, control may be made to switch the screen mode from input mode to display mode.

[0265] The display unit 7402 can also function as an image sensor. For example, by touching the display unit 7402 with the palm or finger, palm prints, fingerprints, etc., can be captured to perform user authentication. Furthermore, by using a backlight that emits near-infrared light or a sensing light source that emits near-infrared light in the display unit, finger veins, palm veins, etc., can also be captured.

[0266] Figure 8A is a schematic diagram showing an example of a cleaning robot.

[0267] The cleaning robot 5100 has a display 5101 on its top surface, multiple cameras 5102 on its sides, a brush 5103, and control buttons 5104. Although not shown in the illustration, the cleaning robot 5100 also has wheels, a suction port, etc. on its underside. The cleaning robot 5100 is also equipped with various sensors, including an infrared sensor, an ultrasonic sensor, an accelerometer, a piezoelectric sensor, a light sensor, and a gyroscope. Furthermore, the cleaning robot 5100 is equipped with a means of wireless communication.

[0268] The cleaning robot 5100 is self-propelled, can detect dirt 5120, and can suck up the dirt through a suction port located on its underside.

[0269] Furthermore, the cleaning robot 5100 can analyze images captured by the camera 5102 to determine the presence or absence of obstacles such as walls, furniture, or steps. If the image analysis detects objects that could become entangled in the brush 5103, such as wiring, it can stop the brush 5103 from rotating.

[0270] The display 5101 can display information such as the remaining battery level and the amount of dirt collected. The path taken by the cleaning robot 5100 may also be displayed on the display 5101. Alternatively, the display 5101 may be a touch panel, and operation buttons 5104 may be provided on the display 5101.

[0271] The cleaning robot 5100 can communicate with a portable electronic device 5140, such as a smartphone. Images captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the cleaning robot 5100 can check the status of the room even when they are away from home. In addition, the display on the display 5101 can be checked on a portable electronic device such as a smartphone.

[0272] A light-emitting device according to one aspect of the present invention can be used in a display 5101.

[0273] The robot 2100 shown in Figure 8B includes a computing unit 2110, an illuminance sensor 2101, a microphone 2102, an upper camera 2103, a speaker 2104, a display 2105, a lower camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0274] The microphone 2102 has the function of detecting the user's voice and ambient sounds. The speaker 2104 has the function of emitting sound. The robot 2100 can communicate with the user using the microphone 2102 and speaker 2104.

[0275] The display 2105 has the function of displaying various types of information. The robot 2100 can display the information desired by the user on the display 2105. The display 2105 may be equipped with a touch panel. The display 2105 may also be a detachable information terminal, and by installing it in a fixed position on the robot 2100, charging and data transfer can be made possible.

[0276] The upper camera 2103 and the lower camera 2106 have the function of imaging the area around the robot 2100. In addition, the obstacle sensor 2107 can detect the presence or absence of obstacles in the direction of travel when the robot 2100 moves forward using the movement mechanism 2108. The robot 2100 can recognize its surrounding environment and move safely using the upper camera 2103, the lower camera 2106 and the obstacle sensor 2107. The light-emitting device according to one aspect of the present invention can be used in the display 2105.

[0277] Figure 8C shows an example of a goggle-type display. The goggle-type display includes, for example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, a connection terminal 5006, a sensor 5007 (including functions for measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), a microphone 5008, a display unit 5002, a support unit 5012, an earphone 5013, etc.

[0278] A light-emitting device according to one aspect of the present invention can be used in the display unit 5001 and the display unit 5002.

[0279] Figure 9 shows an example in which the light-emitting device described in Embodiment 2 is used in a desk lamp, which is a lighting device. The desk lamp shown in Figure 9 has a housing 2001 and a light source 2002, and the lighting device described in Embodiment 3 may be used as the light source 2002.

[0280] Figure 10 shows an example of using the light-emitting device described in Embodiment 2 as an indoor lighting device 3001. Since the light-emitting device described in Embodiment 2 is a light-emitting device with high luminous efficiency, it can be used as a lighting device with low power consumption. Furthermore, since the light-emitting device described in Embodiment 2 can be made to cover a large area, it can be used as a large-area lighting device. In addition, since the light-emitting device described in Embodiment 2 is thin, it can be used as a thin lighting device.

[0281] The light-emitting device described in Embodiment 2 can also be mounted on the windshield and dashboard of an automobile. Figure 11 shows one embodiment in which the light-emitting device described in Embodiment 2 is used on the windshield and dashboard of an automobile. Display areas 5200 to 5203 are displays provided using the light-emitting device described in Embodiment 2.

[0282] Display area 5200 and display area 5201 are display devices equipped with the light-emitting device described in Embodiment 2, which is installed on the windshield of an automobile. The light-emitting device described in Embodiment 2 can be made into a so-called see-through display device, where the opposite side is visible, by making the first electrode and the second electrode from translucent electrodes. If the display is in a see-through state, it can be installed on the windshield of an automobile without obstructing the view. When providing transistors for driving, it is preferable to use translucent transistors such as organic transistors made of organic semiconductor materials or transistors made of oxide semiconductors.

[0283] The display area 5202 is a display device equipped with the light-emitting device described in Embodiment 2, which is provided on the pillar. By displaying images from an imaging means provided on the vehicle body on the display area 5202, the field of view obstructed by the pillar can be compensated for. Similarly, the display area 5203 provided on the dashboard can compensate for the field of view obstructed by the vehicle body by displaying images from an imaging means provided on the outside of the vehicle, thereby compensating for blind spots and enhancing safety. By displaying images in a way that compensates for the parts that are not visible, safety checks can be performed more naturally and without discomfort.

[0284] Display area 5203 can provide various information, such as navigation information, driving speed, engine speed, mileage, and fuel level. The display items and layout can be changed as needed to suit the user's preferences. This information can also be provided in display areas 5200 to 5202. Furthermore, display areas 5200 to 5203 can also be used as illumination devices.

[0285] Figures 12A and 12B also show a foldable portable information terminal 5150. The foldable portable information terminal 5150 comprises a housing 5151, a display area 5152, and a bending section 5153. Figure 12A shows the portable information terminal 5150 in its unfolded state. Figure 12B shows the portable information terminal in its folded state. Despite having a large display area 5152, the portable information terminal 5150 is compact and highly portable when folded.

[0286] The display area 5152 can be folded in half by the bending portion 5153. The bending portion 5153 is composed of an expandable member and a plurality of support members, and when folded, the expandable member extends. The bending portion 5153 is folded to have a radius of curvature of 2 mm or more, preferably 3 mm or more.

[0287] The display area 5152 may also be a touch panel (input / output device) equipped with a touch sensor (input device). A light-emitting device according to one aspect of the present invention can be used in the display area 5152.

[0288] Figures 13A to 13C also show the foldable portable information terminal 9310. Figure 13A shows the portable information terminal 9310 in its unfolded state. Figure 13B shows the portable information terminal 9310 in an intermediate state, either unfolded or folded. Figure 13C shows the portable information terminal 9310 in its folded state. The portable information terminal 9310 offers excellent portability in its folded state and excellent readability of the display due to its seamless, wide display area in its unfolded state.

[0289] The display panel 9311 is supported by three housings 9315 connected by a hinge 9313. The display panel 9311 may also be a touch panel (input / output device) equipped with a touch sensor (input device). Furthermore, the display panel 9311 can be reversibly transformed from an unfolded state to a folded state by bending the two housings 9315 via the hinge 9313. A light-emitting device according to one aspect of the present invention can be used in the display panel 9311.

[0290] Furthermore, the configuration shown in this embodiment can be used by appropriately combining the configurations shown in Embodiments 1 to 4.

[0291] As described above, the application range of the light-emitting device equipped with the light-emitting device described in Embodiment 2 is extremely broad, and this light-emitting device can be applied to electronic devices in all fields. By using the light-emitting device described in Embodiment 2, it is possible to obtain electronic devices with low power consumption.

[0292] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. [Examples]

[0293] <<Synthesis Example 1>> In this example, an organometallic complex representing one aspect of the present invention, shown by structural formula (100) of Embodiment 1, is bis{4,6-dimethyl-2-[5-(4-cyano-2-methylphenyl)-3-methyl-2-pyradinyl-κN]phenyl-κC}(3,7-diethyl-4,6-nonanedionato-κ 2 This document describes the synthesis method of O,O') Iridium(III) (abbreviation: [Ir(dmmppr-mCP)2(debm)]). The structure of [Ir(dmmppr-mCP)2(debm)] is shown below.

[0294] [ka]

[0295] <Step 1: Synthesis of 5-chloro-2-(3,5-dimethylphenyl)-3-methylpyrazine> 4.6 g (22 mmol) of 2-bromo-5-chloro-3-methylpyrazine, 3.3 g (22 mmol) of 3,5-dimethylphenylboronic acid, 9.3 g (44 mmol) of tripotassium phosphate, 50 mL of acetonitrile, and 5 mL of water were placed in a 100 mL round-bottom flask, and the flask was purged with argon. Then, 0.90 g (1.1 mmol) of [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct was added, and the mixture was reacted by irradiating with microwaves (2.45 GHz, 100 W) for 2 hours.

[0296] After the reaction, the resulting reaction mixture was extracted with ethyl acetate. It was then purified by silica column chromatography. A hexane:dichloromethane ratio of 10:1 was used as the developing solvent, gradually increasing the proportion of dichloromethane until the final developing solvent was hexane:dichloromethane in a 2:1 ratio. The resulting fraction was concentrated to obtain 2.3 g of a white solid in 45% yield. Nuclear magnetic resonance (NMR) confirmed that the obtained white solid was 5-chloro-2-(3,5-dimethylphenyl)-3-methylpyrazine. The synthesis scheme for Step 1 is shown in formula (a-1) below.

[0297] [ka]

[0298] <Step 2: Synthesis of 5-(4-cyano-2-methylphenyl)-2-(3,5-dimethylphenyl)-3-methylpyrazine (abbreviation: Hdmmppr-mCP)> 1.2 g (5.2 mmol) of 5-chloro-2-(3,5-dimethylphenyl)-3-methylpyrazine, 1.0 g (6.2 mmol) of 4-cyano-2-methylphenylboronic acid, 3.3 g (16 mmol) of tripotassium phosphate, 45 mL of toluene, and 5 mL of water, synthesized in Step 1, were placed in a 200 mL three-necked flask. The flask was purged with nitrogen, and the mixture was stirred under reduced pressure to degass it. After degassing, 48 mg (0.052 mmol) of tris(dibenzylideneacetone)dipalladium(0) and 100 mg (0.21 mmol) of tris(2,6-dimethoxyphenyl)phosphine were added, and the mixture was stirred under a nitrogen stream at 110°C for 12 hours. The resulting reaction mixture was extracted with toluene. Subsequently, it was purified by silica column chromatography. Hexane:ethyl acetate = 10:1 was used as the developing solvent, followed by hexane:ethyl acetate = 5:1. The resulting fraction was concentrated to obtain a solid. Hexane was added to the obtained solid, and the mixture was filtered by suction to obtain 0.70 g of a white solid in a yield of 41%. Nuclear magnetic resonance (NMR) spectroscopy confirmed that the obtained white solid was Hdmmppr-mCP. The synthesis scheme for Step 2 is shown in the following formula (a-2).

[0299] [ka]

[0300] <Step 3: Synthesis of di-μ-chlorotetrakis{4,6-dimethyl-2-[5-(4-cyano-2-methylphenyl)-3-methyl-2-pyradinyl-κN]phenyl-κC}diiridium(III) (abbreviation: [Ir(dmmppr-mCP)2Cl]2)> In Step 2, 0.66 g (2.1 mmol) of Hdmmppr-mCP, 0.31 g (1.0 mmol) of iridium chloride hydrate, 15 mL of 2-ethoxyethanol, and 5 mL of water were placed in a 100 mL round-bottom flask, and the flask was purged with argon. The reaction vessel was irradiated with microwaves (2.45 GHz, 100 W) for 1 hour to allow the reaction to proceed. After the reaction, ethanol was added to the reaction solution and the mixture was filtered by suction to obtain 0.39 g of a red solid in a yield of 44%. The synthesis scheme for Step 3 is shown in formula (a-3) below.

[0301] [ka]

[0302] <Step 4: Synthesis of [Ir(dmmppr-mCP)2(debm)]> 20 mL of 2-ethoxyethanol, 20.39 g (0.23 mmol) of [Ir(dmmppr-mCP)2Cl], 0.15 g (0.69 mmol) of 3,7-diethylnonane-4,6-dione, and 0.24 g (2.3 mmol) of sodium carbonate were placed in a 100 mL round-bottom flask, and the flask was purged with argon. This reaction vessel was irradiated with microwaves (2.45 GHz, 120 W) for 2 hours to allow the reaction to proceed.

[0303] The resulting reaction mixture was filtered, and the resulting filtrate was concentrated. It was then purified by silica column chromatography. First, hexane:dichloromethane = 1:1 was used as the developing solvent, followed by dichloromethane. The resulting fraction was concentrated to obtain a red solid. The obtained red solid was recrystallized with dichloromethane / ethanol to obtain 0.19 g of red solid in 40% yield. 0.17 g of the obtained red solid was purified by sublimation using the train sublimation method. This was carried out by heating at 270°C for 22 hours under conditions of 2.6 Pa pressure and argon flow rate of 10.6 mL / min. After sublimation purification, 0.12 g of red solid was obtained with a recovery rate of 68%. The synthesis scheme for step 4 is shown in the following formula (a-4).

[0304] [ka]

[0305] Furthermore, nuclear magnetic resonance spectroscopy of the red solid obtained in step 4 above ( 1 The results of the analysis by 1H-NMR are shown below. 1 The 1H-NMR chart is shown in Figure 14. From this, it can be seen that the organometallic complex [Ir(dmmppr-mCP)2(debm)] represented by the above structural formula (100) was obtained in this synthesis example.

[0306] 1 H-NMR.δ(CDCl3):0.14-0.23(m,12H),1.11-1.00(m,8H),1.48(s,6H),1.57-1.64(m,2H),2.36(s,6H),2.41(s ,6H),3.11(s,6H),4.91(s,1H),6.66(s,2H),7.39(d,2H),7.51(d,2H),7.56(s,2H),7.76(s,2H),8.31(s,2H).

[0307] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of a dichloromethane solution of [Ir(dmmppr-mCP)2(debm)] were measured. For the absorption spectrum measurement, an ultraviolet-visible spectrophotometer (JASCO Corporation, V550 model) was used, and the dichloromethane solution (0.0115 mmol / L) was placed in a quartz cell and measured at room temperature. For the emission spectrum measurement, an absolute PL quantum yield analyzer (Hamamatsu Photonics Ltd., C11347-01) was used, and the deoxygenated dichloromethane solution (0.0115 mmol / L) was placed in a quartz cell under a nitrogen atmosphere in a glove box (Bright Co., Ltd., LABstarM13 (1250 / 780)), sealed tightly, and measured at room temperature. The obtained absorption and emission spectrum measurement results are shown in Figure 15. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity.

[0308] Furthermore, in Figure 15, two solid lines are shown; the thin solid line represents the absorption spectrum, and the thick solid line represents the emission spectrum. The absorption spectrum shown in Figure 15 is the result of subtracting the absorption spectrum obtained by measuring only dichloromethane in a quartz cell from the absorption spectrum measured by measuring a dichloromethane solution (0.0115 mmol / L) in a quartz cell.

[0309] As shown in Figure 15, the organometallic complex [Ir(dmmppr-mCP)2(debm)] has an emission peak at 639 nm, and red emission was observed from dichloromethane. [Examples]

[0310] ≪Synthesis Example 2≫ In this embodiment, an organometallic complex representing one aspect of the present invention, structural formula (101) in Embodiment 1, is bis{4-t-butyl-6-methyl-2-[5-(4-cyano-2-methylphenyl)-3-methyl-2-pyradinyl-κN]phenyl-κC}(3,7-diethyl-4,6-nonanedionato-κ 2 This document describes the synthesis method of O,O')iridium(III) (abbreviation: [Ir(tBummppr-mCP)2(debm)]). The structure of [Ir(tBummppr-mCP)2(debm)] is shown below.

[0311] [ka]

[0312] <Step 1: Synthesis of 5-chloro-2-(3-t-butyl-5-methylphenyl)-3-methylpyrazine> 2.5 g (12 mmol) of 2-bromo-5-chloro-3-methylpyrazine, 2.3 g (12 mmol) of 3-t-butyl-5-methylphenylboronic acid, 5.1 g (24 mmol) of tripotassium phosphate, 0.90 g (1.1 mmol) of [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct, 50 mL of acetonitrile, and 5 mL of water were placed in a 100 mL round-bottom flask, and the flask was purged with argon. The reaction was then carried out by irradiation with microwave (2.45 GHz, 100 W) for 2 hours. After the reaction, the resulting reaction mixture was extracted with ethyl acetate. Subsequently, it was purified by silica column chromatography. As the developing solvent, hexane:dichloromethane = 10:1 was used first, and the amount of dichloromethane was gradually increased until dichloromethane was used as the final developing solvent. The resulting fraction was concentrated to obtain 3.1 g of a white solid in 94% yield. Nuclear magnetic resonance (NMR) spectroscopy confirmed that the white solid obtained was 5-chloro-2-(3-t-butyl-5-methylphenyl)-3-methylpyrazine. The synthesis scheme for Step 1 is shown in formula (b-1) below.

[0313] [ka]

[0314] <Step 2: Synthesis of 5-(4-cyano-2-methylphenyl)-2-(3-t-butyl-5-methylphenyl)-3-methylpyrazine> 1.5 g (5.5 mmol) of 5-chloro-2-(3-t-butyl-5-methylphenyl)-3-methylpyrazine synthesized in Step 1, 1.1 g (6.6 mmol) of 4-cyano-2-methylphenylboronic acid, 3.5 g (16 mmol) of tripotassium phosphate, 49 mL of toluene, and 5 mL of water were placed in a 300 mL three-necked flask. The flask was purged with nitrogen, and the mixture was stirred under reduced pressure to degass it. After degassing, 0.050 g (0.054 mmol) of tris(dibenzylideneacetone)dipalladium(0) and 0.098 g (0.22 mmol) of tris(2,6-dimethoxyphenyl)phosphine were added, and the mixture was stirred at 110°C for 1 hour under a nitrogen stream. Next, 0.051 g (0.056 mmol) of tris(dibenzylideneacetone)dipalladium(0) and 0.096 g (0.22 mmol) of tris(2,6-dimethoxyphenyl)phosphine were added, and the mixture was stirred under a nitrogen stream at 110°C for 8 hours. Then, 0.050 g (0.055 mmol) of tris(dibenzylideneacetone)dipalladium(0) and 0.097 g (0.22 mmol) of tris(2,6-dimethoxyphenyl)phosphine were added, and the mixture was stirred under a nitrogen stream at 110°C for 8 hours. The resulting reaction mixture was extracted with toluene. Subsequently, it was purified by silica column chromatography. Hexane:ethyl acetate = 5:1 was used as the developing solvent. The obtained fraction was concentrated to obtain a solid. Hexane was added to the obtained solid, and it was filtered by suction to obtain 1.00 g of a white solid in 51% yield. Nuclear magnetic resonance (NMR) spectroscopy confirmed that the white solid obtained was 5-(4-cyano-2-methylphenyl)-2-(3-t-butyl-5-methylphenyl)-3-methylpyrazine. The synthesis scheme for Step 2 is shown in formula (b-2) below.

[0315] [ka]

[0316] <Step 3: Synthesis of bis{4-t-butyl-6-methyl-2-[5-(4-cyano-2-methylphenyl)-3-methyl-2-pyradinyl-κN]phenyl-κC}(3,7-diethyl-4,6-nonanedionato-κ2O,O')iridium(III) (abbreviation: [Ir(tBummppr-mCP)2(debm)])> 1.26 g (3.55 mmol) of 5-(4-cyano-2-methylphenyl)-2-(3-t-butyl-5-methylphenyl)-3-methylpyrazine (abbreviation: HtBummppr-mCP) synthesized in Step 2, 0.61 g (1.74 mmol) of iridium chloride hydrate, 12 mL of 2-ethoxyethanol, and 4 mL of water were placed in a 100 mL round-bottom flask, and the flask was purged with argon. The reaction vessel was irradiated with microwaves (2.45 GHz, 100 W) for 1 hour to allow the reaction to proceed. The resulting reaction mixture was transferred to a 300 mL three-neck flask and concentrated. To the resulting red solid, 22 mL of N,N-dimethylformamide, 0.80 g (3.7 mmol) of 3,7-diethylnonane-4,6-dione, and 0.93 g (8.7 mmol) of sodium carbonate were added. The flask was purged with nitrogen, and the mixture was stirred under reduced pressure to degass it. The reaction vessel was stirred at 153°C for 4 hours under a nitrogen stream. The resulting reaction mixture was concentrated and filtered, and the resulting filtrate was concentrated. Subsequently, it was purified by silica column chromatography. Hexane:dichloromethane = 3:1 was used as the developing solvent. The resulting fraction was concentrated to obtain a red solid. The obtained red solid was recrystallized with dichloromethane / methanol to obtain 0.73 g of red solid in yield of 38%. 0.71 g of the obtained red solid was purified by sublimation using the train sublimation method. This was carried out by heating at 250°C for 21 hours under conditions of pressure 2.3 Pa and argon flow rate 10.0 mL / min. After sublimation purification, 0.36 g of red solid was obtained with a recovery rate of 51%. The synthesis scheme for step 3 is shown in the following formula (b-3).

[0317] [ka]

[0318] Furthermore, the protons of the red solid obtained in step 3 above ( 1 H) was measured by nuclear magnetic resonance (NMR). The obtained values ​​are shown below. 1 The 1H-NMR chart is shown in Figure 16. From this, it can be seen that the organometallic complex represented by the above-mentioned structural formula (101), [Ir(tBummppr-mCP)2(debm)], was obtained in this synthesis example.

[0319] 1 H-NMR.δ(CDCl3):0.19(t,6H),0.25(t,6H),1.04-1.12(m,8H),1.35(s,18H),1.50(s,6H),1.61-1.65(m,2H),2.4 2(s,6H),3.11(s,6H),4.93(s,1H),6.82(d,2H),7.39(d,2H),7.51(d,2H),7.55(s,2H),7.93(d,2H),8.32(s,2H).

[0320] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of a dichloromethane solution of [Ir(tBummppr-mCP)2(debm)] were measured. For the absorption spectrum measurement, an ultraviolet-visible spectrophotometer (JASCO Corporation, V550 model) was used, and the dichloromethane solution (0.0110 mmol / L) was placed in a quartz cell and measured at room temperature. For the emission spectrum measurement, an absolute PL quantum yield analyzer (Hamamatsu Photonics Ltd., C11347-01) was used, and the deoxygenated dichloromethane solution (0.0110 mmol / L) was placed in a quartz cell under a nitrogen atmosphere in a glove box (Bright Co., Ltd., LABstarM13 (1250 / 780)), sealed tightly, and measured at room temperature. The obtained absorption and emission spectrum measurement results are shown in Figure 17. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. The absorption spectrum shown in Figure 17 is the result of subtracting the absorption spectrum obtained by measuring only dichloromethane in a quartz cell from the absorption spectrum obtained by measuring a dichloromethane solution (0.0110 mmol / L) in a quartz cell.

[0321] As shown in Figure 17, the iridium complex [Ir(tBummppr-mCP)2(debm)] has an emission peak at 632 nm, and red emission was observed from dichloromethane. [Examples]

[0322] In this example, light-emitting devices 1, 2, 3, and 4 were fabricated using an organometallic complex, [Ir(dmmppr-mCP)2(debm)] (structural formula (100)), which is one embodiment of the present invention. The fabrication of each light-emitting device will be explained with reference to Figure 18. The chemical formulas of the materials used in this example are shown below.

[0323] [ka]

[0324] Fabrication of light-emitting devices 1, 2, 3, and 4 First, a first electrode 901, which functions as an anode, was formed by sputtering a film of indium tin oxide (ITO) containing silicon oxide onto a glass substrate 900. The film thickness was 70 nm, and the electrode area was 2 mm × 2 mm.

[0325] Next, as a pretreatment for forming the light-emitting device on the substrate 900, the substrate surface was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

[0326] Then, 1 × 10 -4 The substrate was introduced into a vacuum deposition apparatus where the internal pressure was reduced to approximately Pa. After vacuum firing at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus, the substrate 900 was allowed to cool for about 30 minutes.

[0327] Next, the substrate 900 was fixed to a holder provided in the vacuum deposition apparatus so that the surface on which the first electrode 901 was formed was facing downwards. In this embodiment, we will describe the case in which the hole injection layer 911, hole transport layer 912, light-emitting layer 913, electron transport layer 914, and electron injection layer 915 constituting the EL layer 902 are sequentially formed by the vacuum deposition method.

[0328] 1 × 10 inside the vacuum chamber -4 After reducing the pressure to Pa, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF) and an electron acceptor material (OCHD-001) were co-deposited in a ratio of PCBBiF:OCHD-001 = 1:0.1 (mass ratio) to form a hole injection layer 911 on the first electrode 901. The film thickness was set to 10 nm. Co-deposition is a deposition method in which multiple different substances are evaporated simultaneously from different evaporation sources.

[0329] Next, PCBBiF was deposited at a 90nm layer to form a hole transport layer 912.

[0330] Next, a light-emitting layer 913 was formed on the hole transport layer 912.

[0331] For light-emitting device 1, 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]fl[2,3-b]pyrazine (abbreviation: 9mDBTBPNfpr), PCBBiF, and [Ir(dmmppr-mCP)2(debm)] were co-deposited in a mass ratio of 9mDBTBPNfpr:PCBBiF:[Ir(dmmppr-mCP)2(debm)]=0.7:0.3:0.03, resulting in a film thickness of 40 nm. For light-emitting device 2, 9mDBTBPNfpr:PCBBiF:[Ir(dmmppr-mCP)2(debm)] were co-deposited in a mass ratio of 9mDBTBPNfpr:PCBBiF:[Ir(dmmppr-mCP)2(debm)]=0.7:0.3:0.05, resulting in a film thickness of 40 nm. For light-emitting device 3, co-deposition was performed with a mass ratio of 9mDBTBPNfpr:PCBBiF:[Ir(dmmppr-mCP)2(debm)]=0.7:0.3:0.1, and the film thickness was 40 nm. For light-emitting device 4, co-deposition was performed with a mass ratio of 9mDBTBPNfpr:PCBBiF:[Ir(dmmppr-mCP)2(debm)]=0.7:0.3:0.15, and the film thickness was 40 nm.

[0332] Next, 30 nm of 9 mDBTBPNfpr was deposited on the light-emitting layer 913, followed by 15 nm of NBphen to form the electron transport layer 914.

[0333] Furthermore, a 1 nm layer of lithium fluoride was deposited on the electron transport layer 914 to form an electron injection layer 915.

[0334] Finally, aluminum was deposited onto the electron injection layer 915 to a thickness of 200 nm to form a second electrode 903 that would serve as the cathode, thereby obtaining light-emitting devices 1, 2, 3, and 4. In the above deposition process, resistance heating was used for all depositions.

[0335] Table 1 shows the element structures of the light-emitting devices 1, 2, 3, and 4 obtained as described above.

[0336] [Table 1]

[0337] Furthermore, the fabricated light-emitting devices 1, 2, 3, and 4 were sealed in a glove box under a nitrogen atmosphere to prevent exposure to the air (sealant was applied around the elements, UV treatment was performed during sealing, and heat treatment was performed at 80°C for 1 hour).

[0338] <<Operating characteristics of light-emitting device 1, light-emitting device 2, light-emitting device 3, and light-emitting device 4>> The operating characteristics of each fabricated light-emitting device were measured. The measurements were performed at room temperature (in an atmosphere maintained at 25°C).

[0339] Figure 19 shows the current density-luminance characteristics of light-emitting devices 1, 2, 3, and 4, Figure 20 shows the voltage-luminance characteristics, Figure 21 shows the luminance-current efficiency characteristics, and Figure 22 shows the voltage-current characteristics.

[0340] Also, 1000 cd / m² 2 The main initial characteristic values ​​of light-emitting devices 1, 2, 3, and 4 in the vicinity are shown in Table 2 below.

[0341] [Table 2]

[0342] Furthermore, Figure 23 shows the 1000 cd / m² values ​​for light-emitting devices 1, 2, 3, and 4. 2 The emission spectra in the vicinity are shown. As shown in Figure 23, the emission spectra of light-emitting device 1, light-emitting device 2, light-emitting device 3, and light-emitting device 4 all have a peak around 642 nm.

[0343] Next, reliability tests were performed on light-emitting devices 1, 2, 3, and 4. The results of the reliability tests are shown in Figure 24. In Figure 24, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device's operating time (h). The reliability tests were conducted with a current density of 75 mA / cm². 2 It was done while fixed in place.

[0344] Furthermore, when comparing light-emitting devices 1, 2, 3, and 4, the light-emitting device using the organometallic complex [Ir(dmmppr-mCP)2(debm)], which is one embodiment of the present invention, as the light-emitting layer showed higher reliability as the concentration of [Ir(dmmppr-mCP)2(debm)] decreased. This is thought to be due to the relaxation of the carrier trapping properties by the dopant. In configurations with a small amount of dopant added, the dopant has the ability to trap carriers. By reducing the concentration of this dopant, the trapping properties are relaxed, the driving voltage is reduced, and the localization of carriers within the light-emitting layer is alleviated, resulting in a wider light-emitting region and a longer lifespan. [Examples]

[0345] In this example, a light-emitting device 5 is fabricated using an organometallic complex, [Ir(tBummppr-mCP)2(debm)] (structural formula (101)), which is one aspect of the present invention, and the evaluation results of various properties of the light-emitting device 5 are described. The fabrication of the light-emitting device 5 is generally the same as in Example 3. Therefore, this example mainly describes the differences from Example 3. The chemical formulas of the materials used in this example, which were not shown in Example 3, are shown below.

[0346] [ka]

[0347] Fabrication of light-emitting devices The configuration of the hole injection layer 911, the light-emitting layer 913, and the electron transport layer 914 of the light-emitting device 5 differs from that of the light-emitting devices 1 to 4 shown in Example 3.

[0348] In the light-emitting device 5, PCBBiF and OCHD-001 were co-deposited as the hole injection layer 911, with PCBBiF:OCHD-001 = 1:0.05 (mass ratio). The film thickness was 10 nm, the same as in Example 3.

[0349] Furthermore, 9mDBTBPNfpr, PCBBiF, and [Ir(tBummppr-mCP)2(debm)] were co-deposited as the light-emitting layer 913 in a mass ratio of 9mDBTBPNfpr:PCBBiF:[Ir(tBummppr-mCP)2(debm)] = 0.7:0.3:0.1. The film thickness was set to 30 nm.

[0350] Furthermore, as the electron transport layer 914, mFBPTzn was deposited on the light-emitting layer 913 to a thickness of 10 nm, and then 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenantrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mPn-mDMePyPTzn) and Liq were co-deposited in a ratio of mPn-mDMePyPTzn:Liq = 0.5:0.5 (mass ratio) and with a thickness of 35 nm.

[0351] Table 3 shows the element structure of the light-emitting device 5 obtained as described above.

[0352] [Table 3]

[0353] Furthermore, the fabricated light-emitting device 5 was sealed in a glove box under a nitrogen atmosphere to prevent exposure to the air (a sealing material was applied around the element, and it was UV treated and heat-treated at 80°C for 1 hour during sealing).

[0354] <<Operating characteristics of light-emitting device 5>> The operating characteristics of each fabricated light-emitting device were measured. The measurements were performed at room temperature (in an atmosphere maintained at 25°C).

[0355] Figure 25 shows the current density-luminance characteristics of the light-emitting device 5, Figure 26 shows the voltage-luminance characteristics, Figure 27 shows the luminance-current efficiency characteristics, and Figure 28 shows the voltage-current characteristics.

[0356] Also, 1000 cd / m² 2 The main initial characteristics of the light-emitting device 5 in the vicinity are shown in Table 4 below.

[0357] [Table 4]

[0358] Furthermore, Figure 29 shows the light-emitting device 5 at 1000 cd / m². 2 The emission spectrum in the vicinity is shown. As shown in Figure 29, the emission spectrum of light-emitting device 5 has a peak around 638 nm.

[0359] Next, a reliability test was performed on the light-emitting device 5. The results of the reliability test are shown in Figure 30. In Figure 30, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device's operating time (h). The reliability test was conducted with a current density of 75 mA / cm². 2 It was done while fixed in place.

[0360] Figure 30 shows that the light-emitting device 5 exhibits even better reliability than the light-emitting devices 1 to 4. [Explanation of Symbols]

[0361] 181: First electrode, 182: Second electrode, 183: EL layer, 191: Hole injection layer, 192: Hole transport layer, 193: Light-emitting layer, 194: Electron transport layer, 195: Electron transport layer, 196: Charge generation layer, 197: P-type layer, 198: Electron relay layer, 199: Electron injection buffer layer, 400: Substrate, 401: Electrode, 403: EL layer, 404: Second electrode, 405: Sealing material, 406: Sealing material, 407: Encapsulation substrate, 412: Pad, 420: IC chip, 501: Anode, 502: Cathode, 511: Light-emitting unit, 512: Light-emitting unit, 513: Charge generation layer, 601: So 601: Gate line drive circuit, 602: Pixel section, 603: Gate line drive circuit, 604: Encapsulation substrate, 605: Sealing material, 607: Space, 608: Wiring, 610: Element substrate, 611: Switching FET, 612: Current control FET, 613: Electrode, 614: Insulator, 616: EL layer, 617: Second electrode, 618: Light-emitting device, 623: FET, 900: Substrate, 901: First electrode, 902: EL layer, 903: Second electrode, 911: Hole injection layer, 912: Hole transport layer, 913: Light-emitting layer, 914: Electron transport layer, 915: Electron injection layer, 951: Substrate, 952: Electrode, 9 53: Insulating layer, 954: Partition layer, 955: EL layer, 956: Electrode, 1001: Substrate, 1002: Underlying insulating film, 1003: Gate insulating film, 1006: Gate electrode, 1007: Gate electrode, 1008: Gate electrode, 1020: Interlayer insulating film, 1021: Interlayer insulating film, 1022: Electrode, 1025: Partition, 1028: EL layer, 1029: Second electrode, 1031: Encapsulating substrate, 1032: Sealing material, 1033: Base material, 1035: Black matrix, 1036: Overcoat layer, 1037: Interlayer insulating film, 1040: Pixel area, 1041: Drive circuit area, 1042: Peripheral area ,2001:Housing, 2002:Light source, 2100:Robot, 2101:Illuminance sensor, 2102:Microphone, 2103:Upper camera, 2104:Speaker, 2105:Display, 2106:Lower camera, 2107:Obstacle sensor, 2108:Movement mechanism, 2110:Computer unit, 3001:Lighting device, 5000:Housing, 5001:Display unit, 5002:Display unit, 5003:Speaker, 5004:LED lamp, 5006:Connection terminal, 5007:Sensor, 5008:Microphone, 5012:Support unit, 5013:Earphone, 5100:Cleaning robot,5101: Display, 5102: Camera, 5103: Brush, 5104: Operation button, 5120: Dust, 5140: Portable electronic device, 5150: Portable information terminal, 5151: Housing, 5152: Display area, 5153: Bending part, 5200: Display area, 5201: Display area, 5202: Display area, 5203: Display area, 7101: Housing, 7103: Display unit, 7105: Stand, 7107: Display unit, 7109: Operation key, 7110: Remote control unit, 7201: Main unit, 7202: Housing, 7203: Display unit, 72 04: Keyboard, 7205: External connection port, 7206: Pointing device, 7210: Display unit, 7401: Housing, 7402: Display unit, 7403: Operation buttons, 7404: External connection port, 7405: Speaker, 7406: Microphone, 9310: Personal digital assistant, 9311: Display panel, 9313: Hinge, 9315: Housing, 1024B: First electrode, 1024G: First electrode, 1024R: First electrode, 1024W: First electrode, 1034B: Coloring layer, 1034G: Coloring layer, 1034R: Coloring layer,

Claims

1. It has a pair of electrodes and a light-emitting layer, The light-emitting layer has an organometallic complex, The organometallic complex comprises a ligand containing a pyrazine skeleton and iridium, A light-emitting device wherein the nitrogen at position 1 of the pyrazine skeleton is bonded to the iridium, the carbon at position 3 and position 6 of the pyrazine skeleton are each independently bonded to one of hydrogen, an alkyl group, or an alkoxy group, the carbon at position 5 of the pyrazine skeleton is bonded to an aryl group having a cyano group as a substituent, the carbon at position 2 of the pyrazine skeleton is bonded to an aromatic hydrocarbon group, and a portion of the carbons of the aromatic hydrocarbon group is bonded to the iridium.

2. It has a pair of electrodes and a light-emitting layer, The light-emitting layer has an organometallic complex, The organometallic complex is a light-emitting device comprising a structure represented by general formula (G1). 【Chemistry 1】 (In the formula, A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. A ｒ R represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. １ and R ２ Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

3. It has a pair of electrodes and a light-emitting layer, The light-emitting layer has an organometallic complex, The organometallic complex is a light-emitting device comprising a structure represented by general formula (G2). 【Chemistry 2】 (In the formula, A ｒ R represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. １ and R ２ Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. ３ ~R ６ Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group.

4. It has a pair of electrodes and a light-emitting layer, The light-emitting layer has an organometallic complex, The organometallic complex is a light-emitting device having a structure represented by general formula (G3). 【Transformation 3】 (In the formula, A represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms. A ｒ represents an aryl group having 6 to 25 carbon atoms having at least one cyano group as a substituent. R １ and R ２ each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. L represents a monoanionic ligand.)

5. It has a pair of electrodes and a light-emitting layer, The light-emitting layer has an organometallic complex, The organometallic complex is a light-emitting device having a structure represented by general formula (G4). 【Chemistry 4】 (In the formula, A ｒ R represents an aryl group having 6 to 25 carbon atoms and having at least one cyano group as a substituent. １ and R ２ Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. ３ ~R ６ Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. L represents a monoanionic ligand.

6. In claim 4 or claim 5, The aforementioned monoanionic ligand is a monoanionic bidentate chelate ligand having a β-diketone structure, a monoanionic bidentate chelate ligand having a carboxyl group, a monoanionic bidentate chelate ligand having a phenolic hydroxyl group, a monoanionic bidentate chelate ligand in which both coordinating elements are nitrogen, or an aromatic heterocyclic bidentate ligand that forms a metal-carbon bond with iridium by cyclometalation, and is used in the light-emitting device.

7. In claim 4 or claim 5, The light-emitting device wherein the monoanionic ligand is one of the ligands represented by the following general formulas (L1) to (L6). 【Transformation 5】 (In the formula, R ７１ ~R ９４ Each of these independently represents one of the following: hydrogen, a substituted or unsubstituted C1-C10 alkyl group, a halogen group, a vinyl group, a substituted or unsubstituted C1-C10 haloalkyl group, a substituted or unsubstituted C1-C10 alkoxy group, or a substituted or unsubstituted C1-C10 alkylthio group. １ ~A ３ These independently bond with nitrogen and hydrogen, respectively, sp ２ hybridized carbon or substituent sp ２ The compound carbon represents a hybrid carbon, and the substituent represents one of the following: an alkyl group having 1 to 6 carbon atoms, a halogen group, a haloalkyl group having 1 to 6 carbon atoms, or a phenyl group, B １ ~B ８ These independently bond with nitrogen and hydrogen, respectively, sp ２ hybridized carbon or substituent sp ２ (This represents a hybrid carbon atom, and the substituent represents one of the following: an alkyl group having 1 to 6 carbon atoms, a halogen group, a haloalkyl group having 1 to 6 carbon atoms, or a phenyl group.)

8. It has a pair of electrodes and a light-emitting layer, The light-emitting layer has an organometallic complex, The organometallic complex is a light-emitting device having a structure represented by general formula (G5). 【Transformation 6】 (In the formula, R １ and R ２ Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. ３ ~R ６ Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. ７ ~R １１ Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, a substituted or unsubstituted C3-C12 heteroaryl group, or a cyano group, with at least one representing a cyano group. ７１ ~R ７３ Each of these independently represents one of the following: hydrogen, a C1-C10 alkyl group, a halogen group, a vinyl group, a C1-C10 haloalkyl group, a C1-C10 alkoxy group, or a C1-C10 alkylthio group.

9. It has a pair of electrodes and a light-emitting layer, The light-emitting layer has an organometallic complex, The organometallic complex is a light-emitting device having a structure represented by general formula (G6). 【Transformation 7】 (In the formula, R １ and R ２ Each of these independently represents one of the following: hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. ３ and R ５ Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a halogen group, or a trifluoromethyl group. ７ ~R １１ Each of these independently represents one of the following: hydrogen, a C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, a substituted or unsubstituted C3-C12 heteroaryl group, or a cyano group, with at least one representing a cyano group. ７１ ~R ７３ Each of these independently represents one of the following: hydrogen, a C1-C10 alkyl group, a halogen group, a vinyl group, a C1-C10 haloalkyl group, a C1-C10 alkoxy group, or a C1-C10 alkylthio group.

10. In any one of claims 1 to 9, The light-emitting device comprises a first organic compound having electron transport properties and a second organic compound having hole transport properties.

11. In any one of claims 1 to 9, The light-emitting layer comprises a first organic compound and a second organic compound. A light-emitting device in which the first organic compound and the second organic compound are a combination that forms an excited complex.

12. In any one of claims 1 to 9, The light-emitting layer is a light-emitting device having a TADF material.

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